Merge branch 'bvl-group-trees' into 'master'

Show collapsible tree on the project show page

Closes #30343

See merge request gitlab-org/gitlab-ce!14055

99 files changed, 5069 insertions, 1183 deletions

diff --git a/app/assets/javascripts/dispatcher.js b/app/assets/javascripts/dispatcher.js
index 0a645e5842d..b66652db33b 100644
--- a/app/assets/javascripts/dispatcher.js
+++ b/app/assets/javascripts/dispatcher.js
@@ -73,6 +73,7 @@ import initProjectVisibilitySelector from './project_visibility';
 import GpgBadges from './gpg_badges';
 import UserFeatureHelper from './helpers/user_feature_helper';
 import initChangesDropdown from './init_changes_dropdown';
+import NewGroupChild from './groups/new_group_child';
 import AbuseReports from './abuse_reports';
 import { ajaxGet, convertPermissionToBoolean } from './lib/utils/common_utils';
 import AjaxLoadingSpinner from './ajax_loading_spinner';
@@ -392,10 +393,15 @@ import memberExpirationDate from './member_expiration_date';
           new gl.Activities();
           break;
         case 'groups:show':
+          const newGroupChildWrapper = document.querySelector('.js-new-project-subgroup');
           shortcut_handler = new ShortcutsNavigation();
           new NotificationsForm();
           new NotificationsDropdown();
           new ProjectsList();
+
+          if (newGroupChildWrapper) {
+            new NewGroupChild(newGroupChildWrapper);
+          }
           break;
         case 'groups:group_members:index':
           memberExpirationDate();
diff --git a/app/assets/javascripts/filterable_list.js b/app/assets/javascripts/filterable_list.js
index 6d516a253bb..9e91f72b2ea 100644
--- a/app/assets/javascripts/filterable_list.js
+++ b/app/assets/javascripts/filterable_list.js
@@ -6,10 +6,11 @@ import _ from 'underscore';
  */
 
 export default class FilterableList {
-  constructor(form, filter, holder) {
+  constructor(form, filter, holder, filterInputField = 'filter_groups') {
     this.filterForm = form;
     this.listFilterElement = filter;
     this.listHolderElement = holder;
+    this.filterInputField = filterInputField;
     this.isBusy = false;
   }
 
@@ -32,10 +33,10 @@ export default class FilterableList {
   onFilterInput() {
     const $form = $(this.filterForm);
     const queryData = {};
-    const filterGroupsParam = $form.find('[name="filter_groups"]').val();
+    const filterGroupsParam = $form.find(`[name="${this.filterInputField}"]`).val();
 
     if (filterGroupsParam) {
-      queryData.filter_groups = filterGroupsParam;
+      queryData[this.filterInputField] = filterGroupsParam;
     }
 
     this.filterResults(queryData);
diff --git a/app/assets/javascripts/groups/components/app.vue b/app/assets/javascripts/groups/components/app.vue
new file mode 100644
index 00000000000..2c0b6ab4ea8
--- /dev/null
+++ b/app/assets/javascripts/groups/components/app.vue
@@ -0,0 +1,194 @@
+<script>
+/* global Flash */
+
+import eventHub from '../event_hub';
+import { getParameterByName } from '../../lib/utils/common_utils';
+import loadingIcon from '../../vue_shared/components/loading_icon.vue';
+import { COMMON_STR } from '../constants';
+
+import groupsComponent from './groups.vue';
+
+export default {
+  components: {
+    loadingIcon,
+    groupsComponent,
+  },
+  props: {
+    store: {
+      type: Object,
+      required: true,
+    },
+    service: {
+      type: Object,
+      required: true,
+    },
+    hideProjects: {
+      type: Boolean,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      isLoading: true,
+      isSearchEmpty: false,
+      searchEmptyMessage: '',
+    };
+  },
+  computed: {
+    groups() {
+      return this.store.getGroups();
+    },
+    pageInfo() {
+      return this.store.getPaginationInfo();
+    },
+  },
+  methods: {
+    fetchGroups({ parentId, page, filterGroupsBy, sortBy, archived, updatePagination }) {
+      return this.service.getGroups(parentId, page, filterGroupsBy, sortBy, archived)
+                .then((res) => {
+                  if (updatePagination) {
+                    this.updatePagination(res.headers);
+                  }
+
+                  return res;
+                })
+                .then(res => res.json())
+                .catch(() => {
+                  this.isLoading = false;
+                  $.scrollTo(0);
+
+                  Flash(COMMON_STR.FAILURE);
+                });
+    },
+    fetchAllGroups() {
+      const page = getParameterByName('page') || null;
+      const sortBy = getParameterByName('sort') || null;
+      const archived = getParameterByName('archived') || null;
+      const filterGroupsBy = getParameterByName('filter') || null;
+
+      this.isLoading = true;
+      // eslint-disable-next-line promise/catch-or-return
+      this.fetchGroups({
+        page,
+        filterGroupsBy,
+        sortBy,
+        archived,
+        updatePagination: true,
+      }).then((res) => {
+        this.isLoading = false;
+        this.updateGroups(res, Boolean(filterGroupsBy));
+      });
+    },
+    fetchPage(page, filterGroupsBy, sortBy, archived) {
+      this.isLoading = true;
+
+      // eslint-disable-next-line promise/catch-or-return
+      this.fetchGroups({
+        page,
+        filterGroupsBy,
+        sortBy,
+        archived,
+        updatePagination: true,
+      }).then((res) => {
+        this.isLoading = false;
+        $.scrollTo(0);
+
+        const currentPath = gl.utils.mergeUrlParams({ page }, window.location.href);
+        window.history.replaceState({
+          page: currentPath,
+        }, document.title, currentPath);
+
+        this.updateGroups(res);
+      });
+    },
+    toggleChildren(group) {
+      const parentGroup = group;
+      if (!parentGroup.isOpen) {
+        if (parentGroup.children.length === 0) {
+          parentGroup.isChildrenLoading = true;
+          // eslint-disable-next-line promise/catch-or-return
+          this.fetchGroups({
+            parentId: parentGroup.id,
+          }).then((res) => {
+            this.store.setGroupChildren(parentGroup, res);
+          }).catch(() => {
+            parentGroup.isChildrenLoading = false;
+          });
+        } else {
+          parentGroup.isOpen = true;
+        }
+      } else {
+        parentGroup.isOpen = false;
+      }
+    },
+    leaveGroup(group, parentGroup) {
+      const targetGroup = group;
+      targetGroup.isBeingRemoved = true;
+      this.service.leaveGroup(targetGroup.leavePath)
+        .then(res => res.json())
+        .then((res) => {
+          $.scrollTo(0);
+          this.store.removeGroup(targetGroup, parentGroup);
+          Flash(res.notice, 'notice');
+        })
+        .catch((err) => {
+          let message = COMMON_STR.FAILURE;
+          if (err.status === 403) {
+            message = COMMON_STR.LEAVE_FORBIDDEN;
+          }
+          Flash(message);
+          targetGroup.isBeingRemoved = false;
+        });
+    },
+    updatePagination(headers) {
+      this.store.setPaginationInfo(headers);
+    },
+    updateGroups(groups, fromSearch) {
+      this.isSearchEmpty = groups ? groups.length === 0 : false;
+      if (fromSearch) {
+        this.store.setSearchedGroups(groups);
+      } else {
+        this.store.setGroups(groups);
+      }
+    },
+  },
+  created() {
+    this.searchEmptyMessage = this.hideProjects ?
+      COMMON_STR.GROUP_SEARCH_EMPTY : COMMON_STR.GROUP_PROJECT_SEARCH_EMPTY;
+
+    eventHub.$on('fetchPage', this.fetchPage);
+    eventHub.$on('toggleChildren', this.toggleChildren);
+    eventHub.$on('leaveGroup', this.leaveGroup);
+    eventHub.$on('updatePagination', this.updatePagination);
+    eventHub.$on('updateGroups', this.updateGroups);
+  },
+  mounted() {
+    this.fetchAllGroups();
+  },
+  beforeDestroy() {
+    eventHub.$off('fetchPage', this.fetchPage);
+    eventHub.$off('toggleChildren', this.toggleChildren);
+    eventHub.$off('leaveGroup', this.leaveGroup);
+    eventHub.$off('updatePagination', this.updatePagination);
+    eventHub.$off('updateGroups', this.updateGroups);
+  },
+};
+</script>
+
+<template>
+  <div>
+    <loading-icon
+      class="loading-animation prepend-top-20"
+      size="2"
+      v-if="isLoading"
+      :label="s__('GroupsTree|Loading groups')"
+    />
+    <groups-component
+      v-if="!isLoading"
+      :groups="groups"
+      :search-empty="isSearchEmpty"
+      :search-empty-message="searchEmptyMessage"
+      :page-info="pageInfo"
+    />
+  </div>
+</template>
diff --git a/app/assets/javascripts/groups/components/group_folder.vue b/app/assets/javascripts/groups/components/group_folder.vue
index 7cc6c4b0359..e60221fa08d 100644
--- a/app/assets/javascripts/groups/components/group_folder.vue
+++ b/app/assets/javascripts/groups/components/group_folder.vue
@@ -1,15 +1,27 @@
 <script>
+import { n__ } from '../../locale';
+import { MAX_CHILDREN_COUNT } from '../constants';
+
 export default {
   props: {
-    groups: {
-      type: Object,
-      required: true,
-    },
-    baseGroup: {
+    parentGroup: {
       type: Object,
       required: false,
       default: () => ({}),
     },
+    groups: {
+      type: Array,
+      required: false,
+      default: () => ([]),
+    },
+  },
+  computed: {
+    hasMoreChildren() {
+      return this.parentGroup.childrenCount > MAX_CHILDREN_COUNT;
+    },
+    moreChildrenStats() {
+      return n__('One more item', '%d more items', this.parentGroup.childrenCount - this.parentGroup.children.length);
+    },
   },
 };
 </script>
@@ -20,8 +32,20 @@ export default {
       v-for="(group, index) in groups"
       :key="index"
       :group="group"
-      :base-group="baseGroup"
-      :collection="groups"
+      :parent-group="parentGroup"
     />
+    <li
+      v-if="hasMoreChildren"
+      class="group-row">
+      <a
+        :href="parentGroup.relativePath"
+        class="group-row-contents has-more-items">
+        <i
+          class="fa fa-external-link"
+          aria-hidden="true"
+        />
+        {{moreChildrenStats}}
+      </a>
+    </li>
   </ul>
 </template>
diff --git a/app/assets/javascripts/groups/components/group_item.vue b/app/assets/javascripts/groups/components/group_item.vue
index 2060410e991..356a95c05ca 100644
--- a/app/assets/javascripts/groups/components/group_item.vue
+++ b/app/assets/javascripts/groups/components/group_item.vue
@@ -2,49 +2,28 @@
 import identicon from '../../vue_shared/components/identicon.vue';
 import eventHub from '../event_hub';
 
+import itemCaret from './item_caret.vue';
+import itemTypeIcon from './item_type_icon.vue';
+import itemStats from './item_stats.vue';
+import itemActions from './item_actions.vue';
+
 export default {
   components: {
     identicon,
+    itemCaret,
+    itemTypeIcon,
+    itemStats,
+    itemActions,
   },
   props: {
-    group: {
-      type: Object,
-      required: true,
-    },
-    baseGroup: {
+    parentGroup: {
       type: Object,
       required: false,
       default: () => ({}),
     },
-    collection: {
+    group: {
       type: Object,
-      required: false,
-      default: () => ({}),
-    },
-  },
-  methods: {
-    onClickRowGroup(e) {
-      e.stopPropagation();
-
-      // Skip for buttons
-      if (!(e.target.tagName === 'A') && !(e.target.tagName === 'I' && e.target.parentElement.tagName === 'A')) {
-        if (this.group.hasSubgroups) {
-          eventHub.$emit('toggleSubGroups', this.group);
-        } else {
-          window.location.href = this.group.groupPath;
-        }
-      }
-    },
-    onLeaveGroup(e) {
-      e.preventDefault();
-
-      // eslint-disable-next-line no-alert
-      if (confirm(`Are you sure you want to leave the "${this.group.fullName}" group?`)) {
-        this.leaveGroup();
-      }
-    },
-    leaveGroup() {
-      eventHub.$emit('leaveGroup', this.group, this.collection);
+      required: true,
     },
   },
   computed: {
@@ -53,51 +32,33 @@ export default {
     },
     rowClass() {
       return {
-        'group-row': true,
         'is-open': this.group.isOpen,
-        'has-subgroups': this.group.hasSubgroups,
-        'no-description': !this.group.description,
+        'has-children': this.hasChildren,
+        'has-description': this.group.description,
+        'being-removed': this.group.isBeingRemoved,
       };
     },
-    visibilityIcon() {
-      return {
-        fa: true,
-        'fa-globe': this.group.visibility === 'public',
-        'fa-shield': this.group.visibility === 'internal',
-        'fa-lock': this.group.visibility === 'private',
-      };
+    hasChildren() {
+      return this.group.childrenCount > 0;
     },
-    fullPath() {
-      let fullPath = '';
-
-      if (this.group.isOrphan) {
-        // check if current group is baseGroup
-        if (Object.keys(this.baseGroup).length > 0 && this.baseGroup !== this.group) {
-          // Remove baseGroup prefix from our current group.fullName. e.g:
-          // baseGroup.fullName: `level1`
-          // group.fullName: `level1 / level2 / level3`
-          // Result: `level2 / level3`
-          const gfn = this.group.fullName;
-          const bfn = this.baseGroup.fullName;
-          const length = bfn.length;
-          const start = gfn.indexOf(bfn);
-          const extraPrefixChars = 3;
-
-          fullPath = gfn.substr(start + length + extraPrefixChars);
+    hasAvatar() {
+      return this.group.avatarUrl !== null;
+    },
+    isGroup() {
+      return this.group.type === 'group';
+    },
+  },
+  methods: {
+    onClickRowGroup(e) {
+      const NO_EXPAND_CLS = 'no-expand';
+      if (!(e.target.classList.contains(NO_EXPAND_CLS) ||
+            e.target.parentElement.classList.contains(NO_EXPAND_CLS))) {
+        if (this.hasChildren) {
+          eventHub.$emit('toggleChildren', this.group);
         } else {
-          fullPath = this.group.fullName;
+          gl.utils.visitUrl(this.group.relativePath);
         }
-      } else {
-        fullPath = this.group.name;
       }
-
-      return fullPath;
-    },
-    hasGroups() {
-      return Object.keys(this.group.subGroups).length > 0;
-    },
-    hasAvatar() {
-      return this.group.avatarUrl && this.group.avatarUrl.indexOf('/assets/no_group_avatar') === -1;
     },
   },
 };
@@ -108,98 +69,36 @@ export default {
     @click.stop="onClickRowGroup"
     :id="groupDomId"
     :class="rowClass"
+    class="group-row"
     >
     <div
       class="group-row-contents">
-      <div
-        class="controls">
-        <a
-          v-if="group.canEdit"
-          class="edit-group btn"
-          :href="group.editPath">
-          <i
-            class="fa fa-cogs"
-            aria-hidden="true"
-          >
-          </i>
-        </a>
-        <a
-          @click="onLeaveGroup"
-          :href="group.leavePath"
-          class="leave-group btn"
-          title="Leave this group">
-          <i
-            class="fa fa-sign-out"
-            aria-hidden="true"
-          >
-          </i>
-        </a>
-      </div>
-      <div
-        class="stats">
-        <span
-          class="number-projects">
-          <i
-            class="fa fa-bookmark"
-            aria-hidden="true"
-          >
-          </i>
-          {{group.numberProjects}}
-        </span>
-        <span
-          class="number-users">
-          <i
-            class="fa fa-users"
-            aria-hidden="true"
-          >
-          </i>
-          {{group.numberUsers}}
-        </span>
-        <span
-          class="group-visibility">
-          <i
-            :class="visibilityIcon"
-            aria-hidden="true"
-          >
-          </i>
-        </span>
-      </div>
+      <item-actions
+        v-if="isGroup"
+        :group="group"
+        :parent-group="parentGroup"
+      />
+      <item-stats
+        :item="group"
+      />
       <div
         class="folder-toggle-wrap">
-        <span
-          class="folder-caret"
-          v-if="group.hasSubgroups">
-          <i
-            v-if="group.isOpen"
-            class="fa fa-caret-down"
-            aria-hidden="true"
-          >
-          </i>
-          <i
-            v-if="!group.isOpen"
-            class="fa fa-caret-right"
-            aria-hidden="true"
-          >
-          </i>
-        </span>
-        <span class="folder-icon">
-          <i
-            v-if="group.isOpen"
-            class="fa fa-folder-open"
-            aria-hidden="true"
-          >
-          </i>
-          <i
-            v-if="!group.isOpen"
-            class="fa fa-folder"
-            aria-hidden="true">
-          </i>
-        </span>
+        <item-caret
+          :is-group-open="group.isOpen"
+        />
+        <item-type-icon
+          :item-type="group.type"
+          :is-group-open="group.isOpen"
+        />
       </div>
       <div
-        class="avatar-container s40 hidden-xs">
+        class="avatar-container s40 hidden-xs"
+        :class="{ 'content-loading': group.isChildrenLoading }"
+      >
         <a
-          :href="group.groupPath">
+          :href="group.relativePath"
+          class="no-expand"
+        >
           <img
             v-if="hasAvatar"
             class="avatar s40"
@@ -215,19 +114,22 @@ export default {
       <div
         class="title">
         <a
-          :href="group.groupPath">{{fullPath}}</a>
-        <template v-if="group.permissions.humanGroupAccess">
-        as
-        <span class="access-type">{{group.permissions.humanGroupAccess}}</span>
-        </template>
+          :href="group.relativePath"
+          class="no-expand">{{group.fullName}}</a>
+        <span
+          v-if="group.permission"
+          class="access-type"
+        >
+          {{s__('GroupsTreeRole|as')}} {{group.permission}}
+        </span>
       </div>
       <div
         class="description">{{group.description}}</div>
     </div>
     <group-folder
-      v-if="group.isOpen && hasGroups"
-      :groups="group.subGroups"
-      :baseGroup="group"
+      v-if="group.isOpen && hasChildren"
+      :parent-group="group"
+      :groups="group.children"
     />
   </li>
 </template>
diff --git a/app/assets/javascripts/groups/components/groups.vue b/app/assets/javascripts/groups/components/groups.vue
index d17a43b048a..75a2bf34887 100644
--- a/app/assets/javascripts/groups/components/groups.vue
+++ b/app/assets/javascripts/groups/components/groups.vue
@@ -4,24 +4,33 @@ import eventHub from '../event_hub';
 import { getParameterByName } from '../../lib/utils/common_utils';
 
 export default {
+  components: {
+    tablePagination,
+  },
   props: {
     groups: {
-      type: Object,
+      type: Array,
       required: true,
     },
     pageInfo: {
       type: Object,
       required: true,
     },
-  },
-  components: {
-    tablePagination,
+    searchEmpty: {
+      type: Boolean,
+      required: true,
+    },
+    searchEmptyMessage: {
+      type: String,
+      required: true,
+    },
   },
   methods: {
     change(page) {
       const filterGroupsParam = getParameterByName('filter_groups');
       const sortParam = getParameterByName('sort');
-      eventHub.$emit('fetchPage', page, filterGroupsParam, sortParam);
+      const archivedParam = getParameterByName('archived');
+      eventHub.$emit('fetchPage', page, filterGroupsParam, sortParam, archivedParam);
     },
   },
 };
@@ -29,10 +38,17 @@ export default {
 
 <template>
   <div class="groups-list-tree-container">
+    <div
+      v-if="searchEmpty"
+      class="has-no-search-results">
+      {{searchEmptyMessage}}
+    </div>
     <group-folder
+      v-if="!searchEmpty"
       :groups="groups"
     />
     <table-pagination
+      v-if="!searchEmpty"
       :change="change"
       :pageInfo="pageInfo"
     />
diff --git a/app/assets/javascripts/groups/components/item_actions.vue b/app/assets/javascripts/groups/components/item_actions.vue
new file mode 100644
index 00000000000..7eff19e2e5a
--- /dev/null
+++ b/app/assets/javascripts/groups/components/item_actions.vue
@@ -0,0 +1,93 @@
+<script>
+import { s__ } from '../../locale';
+import tooltip from '../../vue_shared/directives/tooltip';
+import PopupDialog from '../../vue_shared/components/popup_dialog.vue';
+import eventHub from '../event_hub';
+import { COMMON_STR } from '../constants';
+
+export default {
+  components: {
+    PopupDialog,
+  },
+  directives: {
+    tooltip,
+  },
+  props: {
+    parentGroup: {
+      type: Object,
+      required: false,
+      default: () => ({}),
+    },
+    group: {
+      type: Object,
+      required: true,
+    },
+  },
+  data() {
+    return {
+      dialogStatus: false,
+    };
+  },
+  computed: {
+    leaveBtnTitle() {
+      return COMMON_STR.LEAVE_BTN_TITLE;
+    },
+    editBtnTitle() {
+      return COMMON_STR.EDIT_BTN_TITLE;
+    },
+    leaveConfirmationMessage() {
+      return s__(`GroupsTree|Are you sure you want to leave the "${this.group.fullName}" group?`);
+    },
+  },
+  methods: {
+    onLeaveGroup() {
+      this.dialogStatus = true;
+    },
+    leaveGroup(leaveConfirmed) {
+      this.dialogStatus = false;
+      if (leaveConfirmed) {
+        eventHub.$emit('leaveGroup', this.group, this.parentGroup);
+      }
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="controls">
+    <a
+      v-tooltip
+      v-if="group.canEdit"
+      :href="group.editPath"
+      :title="editBtnTitle"
+      :aria-label="editBtnTitle"
+      data-container="body"
+      class="edit-group btn no-expand">
+      <i
+        class="fa fa-cogs"
+        aria-hidden="true"/>
+    </a>
+    <a
+      v-tooltip
+      v-if="group.canLeave"
+      @click.prevent="onLeaveGroup"
+      :href="group.leavePath"
+      :title="leaveBtnTitle"
+      :aria-label="leaveBtnTitle"
+      data-container="body"
+      class="leave-group btn no-expand">
+      <i
+        class="fa fa-sign-out"
+        aria-hidden="true"/>
+    </a>
+    <popup-dialog
+      v-show="dialogStatus"
+      :primary-button-label="__('Leave')"
+      kind="warning"
+      :title="__('Are you sure?')"
+      :text="__('Are you sure you want to leave this group?')"
+      :body="leaveConfirmationMessage"
+      @submit="leaveGroup"
+    />
+  </div>
+</template>
diff --git a/app/assets/javascripts/groups/components/item_caret.vue b/app/assets/javascripts/groups/components/item_caret.vue
new file mode 100644
index 00000000000..959b984816f
--- /dev/null
+++ b/app/assets/javascripts/groups/components/item_caret.vue
@@ -0,0 +1,25 @@
+<script>
+export default {
+  props: {
+    isGroupOpen: {
+      type: Boolean,
+      required: true,
+      default: false,
+    },
+  },
+  computed: {
+    iconClass() {
+      return this.isGroupOpen ? 'fa-caret-down' : 'fa-caret-right';
+    },
+  },
+};
+</script>
+
+<template>
+  <span class="folder-caret">
+    <i
+      :class="iconClass"
+      class="fa"
+      aria-hidden="true"/>
+  </span>
+</template>
diff --git a/app/assets/javascripts/groups/components/item_stats.vue b/app/assets/javascripts/groups/components/item_stats.vue
new file mode 100644
index 00000000000..9f8ac138fc3
--- /dev/null
+++ b/app/assets/javascripts/groups/components/item_stats.vue
@@ -0,0 +1,98 @@
+<script>
+import tooltip from '../../vue_shared/directives/tooltip';
+import { ITEM_TYPE, VISIBILITY_TYPE_ICON, GROUP_VISIBILITY_TYPE, PROJECT_VISIBILITY_TYPE } from '../constants';
+
+export default {
+  directives: {
+    tooltip,
+  },
+  props: {
+    item: {
+      type: Object,
+      required: true,
+    },
+  },
+  computed: {
+    visibilityIcon() {
+      return VISIBILITY_TYPE_ICON[this.item.visibility];
+    },
+    visibilityTooltip() {
+      if (this.item.type === ITEM_TYPE.GROUP) {
+        return GROUP_VISIBILITY_TYPE[this.item.visibility];
+      }
+      return PROJECT_VISIBILITY_TYPE[this.item.visibility];
+    },
+    isProject() {
+      return this.item.type === ITEM_TYPE.PROJECT;
+    },
+    isGroup() {
+      return this.item.type === ITEM_TYPE.GROUP;
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="stats">
+    <span
+      v-tooltip
+      v-if="isGroup"
+      :title="s__('Subgroups')"
+      class="number-subgroups"
+      data-placement="top"
+      data-container="body">
+      <i
+        class="fa fa-folder"
+        aria-hidden="true"
+      />
+      {{item.subgroupCount}}
+    </span>
+    <span
+      v-tooltip
+      v-if="isGroup"
+      :title="s__('Projects')"
+      class="number-projects"
+      data-placement="top"
+      data-container="body">
+      <i
+        class="fa fa-bookmark"
+        aria-hidden="true"
+      />
+      {{item.projectCount}}
+    </span>
+    <span
+      v-tooltip
+      v-if="isGroup"
+      :title="s__('Members')"
+      class="number-users"
+      data-placement="top"
+      data-container="body">
+      <i
+        class="fa fa-users"
+        aria-hidden="true"
+      />
+      {{item.memberCount}}
+    </span>
+    <span
+      v-if="isProject"
+      class="project-stars">
+      <i
+        class="fa fa-star"
+        aria-hidden="true"
+      />
+      {{item.starCount}}
+    </span>
+    <span
+      v-tooltip
+      :title="visibilityTooltip"
+      data-placement="left"
+      data-container="body"
+      class="item-visibility">
+      <i
+        :class="visibilityIcon"
+        class="fa"
+        aria-hidden="true"
+      />
+    </span>
+  </div>
+</template>
diff --git a/app/assets/javascripts/groups/components/item_type_icon.vue b/app/assets/javascripts/groups/components/item_type_icon.vue
new file mode 100644
index 00000000000..c02a8ad6d8c
--- /dev/null
+++ b/app/assets/javascripts/groups/components/item_type_icon.vue
@@ -0,0 +1,34 @@
+<script>
+import { ITEM_TYPE } from '../constants';
+
+export default {
+  props: {
+    itemType: {
+      type: String,
+      required: true,
+    },
+    isGroupOpen: {
+      type: Boolean,
+      required: true,
+      default: false,
+    },
+  },
+  computed: {
+    iconClass() {
+      if (this.itemType === ITEM_TYPE.GROUP) {
+        return this.isGroupOpen ? 'fa-folder-open' : 'fa-folder';
+      }
+      return 'fa-bookmark';
+    },
+  },
+};
+</script>
+
+<template>
+  <span class="item-type-icon">
+    <i
+      :class="iconClass"
+      class="fa"
+      aria-hidden="true"/>
+  </span>
+</template>
diff --git a/app/assets/javascripts/groups/constants.js b/app/assets/javascripts/groups/constants.js
new file mode 100644
index 00000000000..6fde41414b3
--- /dev/null
+++ b/app/assets/javascripts/groups/constants.js
@@ -0,0 +1,35 @@
+import { __, s__ } from '../locale';
+
+export const MAX_CHILDREN_COUNT = 20;
+
+export const COMMON_STR = {
+  FAILURE: __('An error occurred. Please try again.'),
+  LEAVE_FORBIDDEN: s__('GroupsTree|Failed to leave the group. Please make sure you are not the only owner.'),
+  LEAVE_BTN_TITLE: s__('GroupsTree|Leave this group'),
+  EDIT_BTN_TITLE: s__('GroupsTree|Edit group'),
+  GROUP_SEARCH_EMPTY: s__('GroupsTree|Sorry, no groups matched your search'),
+  GROUP_PROJECT_SEARCH_EMPTY: s__('GroupsTree|Sorry, no groups or projects matched your search'),
+};
+
+export const ITEM_TYPE = {
+  PROJECT: 'project',
+  GROUP: 'group',
+};
+
+export const GROUP_VISIBILITY_TYPE = {
+  public: __('Public - The group and any public projects can be viewed without any authentication.'),
+  internal: __('Internal - The group and any internal projects can be viewed by any logged in user.'),
+  private: __('Private - The group and its projects can only be viewed by members.'),
+};
+
+export const PROJECT_VISIBILITY_TYPE = {
+  public: __('Public - The project can be accessed without any authentication.'),
+  internal: __('Internal - The project can be accessed by any logged in user.'),
+  private: __('Private - Project access must be granted explicitly to each user.'),
+};
+
+export const VISIBILITY_TYPE_ICON = {
+  public: 'fa-globe',
+  internal: 'fa-shield',
+  private: 'fa-lock',
+};
diff --git a/app/assets/javascripts/groups/groups_filterable_list.js b/app/assets/javascripts/groups/groups_filterable_list.js
index 83b102764ba..2db233b09da 100644
--- a/app/assets/javascripts/groups/groups_filterable_list.js
+++ b/app/assets/javascripts/groups/groups_filterable_list.js
@@ -3,12 +3,13 @@ import eventHub from './event_hub';
 import { getParameterByName } from '../lib/utils/common_utils';
 
 export default class GroupFilterableList extends FilterableList {
-  constructor({ form, filter, holder, filterEndpoint, pagePath }) {
-    super(form, filter, holder);
+  constructor({ form, filter, holder, filterEndpoint, pagePath, dropdownSel, filterInputField }) {
+    super(form, filter, holder, filterInputField);
     this.form = form;
     this.filterEndpoint = filterEndpoint;
     this.pagePath = pagePath;
-    this.$dropdown = $('.js-group-filter-dropdown-wrap');
+    this.filterInputField = filterInputField;
+    this.$dropdown = $(dropdownSel);
   }
 
   getFilterEndpoint() {
@@ -24,30 +25,34 @@ export default class GroupFilterableList extends FilterableList {
   bindEvents() {
     super.bindEvents();
 
-    this.onFormSubmitWrapper = this.onFormSubmit.bind(this);
     this.onFilterOptionClikWrapper = this.onOptionClick.bind(this);
 
-    this.filterForm.addEventListener('submit', this.onFormSubmitWrapper);
     this.$dropdown.on('click', 'a', this.onFilterOptionClikWrapper);
   }
 
-  onFormSubmit(e) {
-    e.preventDefault();
-
-    const $form = $(this.form);
-    const filterGroupsParam = $form.find('[name="filter_groups"]').val();
+  onFilterInput() {
     const queryData = {};
+    const $form = $(this.form);
+    const archivedParam = getParameterByName('archived', window.location.href);
+    const filterGroupsParam = $form.find(`[name="${this.filterInputField}"]`).val();
 
     if (filterGroupsParam) {
-      queryData.filter_groups = filterGroupsParam;
+      queryData[this.filterInputField] = filterGroupsParam;
+    }
+
+    if (archivedParam) {
+      queryData.archived = archivedParam;
     }
 
     this.filterResults(queryData);
-    this.setDefaultFilterOption();
+
+    if (this.setDefaultFilterOption) {
+      this.setDefaultFilterOption();
+    }
   }
 
   setDefaultFilterOption() {
-    const defaultOption = $.trim(this.$dropdown.find('.dropdown-menu a:first-child').text());
+    const defaultOption = $.trim(this.$dropdown.find('.dropdown-menu li.js-filter-sort-order a').first().text());
     this.$dropdown.find('.dropdown-label').text(defaultOption);
   }
 
@@ -55,23 +60,42 @@ export default class GroupFilterableList extends FilterableList {
     e.preventDefault();
 
     const queryData = {};
-    const sortParam = getParameterByName('sort', e.currentTarget.href);
+
+    // Get type of option selected from dropdown
+    const currentTargetClassList = e.currentTarget.parentElement.classList;
+    const isOptionFilterBySort = currentTargetClassList.contains('js-filter-sort-order');
+    const isOptionFilterByArchivedProjects = currentTargetClassList.contains('js-filter-archived-projects');
+
+    // Get option query param, also preserve currently applied query param
+    const sortParam = getParameterByName('sort', isOptionFilterBySort ? e.currentTarget.href : window.location.href);
+    const archivedParam = getParameterByName('archived', isOptionFilterByArchivedProjects ? e.currentTarget.href : window.location.href);
 
     if (sortParam) {
       queryData.sort = sortParam;
     }
 
+    if (archivedParam) {
+      queryData.archived = archivedParam;
+    }
+
     this.filterResults(queryData);
 
     // Active selected option
-    this.$dropdown.find('.dropdown-label').text($.trim(e.currentTarget.text));
+    if (isOptionFilterBySort) {
+      this.$dropdown.find('.dropdown-label').text($.trim(e.currentTarget.text));
+      this.$dropdown.find('.dropdown-menu li.js-filter-sort-order a').removeClass('is-active');
+    } else if (isOptionFilterByArchivedProjects) {
+      this.$dropdown.find('.dropdown-menu li.js-filter-archived-projects a').removeClass('is-active');
+    }
+
+    $(e.target).addClass('is-active');
 
     // Clear current value on search form
-    this.form.querySelector('[name="filter_groups"]').value = '';
+    this.form.querySelector(`[name="${this.filterInputField}"]`).value = '';
   }
 
   onFilterSuccess(data, xhr, queryData) {
-    super.onFilterSuccess(data, xhr, queryData);
+    const currentPath = this.getPagePath(queryData);
 
     const paginationData = {
       'X-Per-Page': xhr.getResponseHeader('X-Per-Page'),
@@ -82,7 +106,11 @@ export default class GroupFilterableList extends FilterableList {
       'X-Prev-Page': xhr.getResponseHeader('X-Prev-Page'),
     };
 
-    eventHub.$emit('updateGroups', data);
+    window.history.replaceState({
+      page: currentPath,
+    }, document.title, currentPath);
+
+    eventHub.$emit('updateGroups', data, Object.prototype.hasOwnProperty.call(queryData, this.filterInputField));
     eventHub.$emit('updatePagination', paginationData);
   }
 }
diff --git a/app/assets/javascripts/groups/index.js b/app/assets/javascripts/groups/index.js
index 600bae24b52..8b850765a1b 100644
--- a/app/assets/javascripts/groups/index.js
+++ b/app/assets/javascripts/groups/index.js
@@ -1,16 +1,17 @@
 import Vue from 'vue';
-import Flash from '../flash';
+import Translate from '../vue_shared/translate';
 import GroupFilterableList from './groups_filterable_list';
-import GroupsComponent from './components/groups.vue';
-import GroupFolder from './components/group_folder.vue';
-import GroupItem from './components/group_item.vue';
-import GroupsStore from './stores/groups_store';
-import GroupsService from './services/groups_service';
-import eventHub from './event_hub';
-import { getParameterByName } from '../lib/utils/common_utils';
+import GroupsStore from './store/groups_store';
+import GroupsService from './service/groups_service';
+
+import groupsApp from './components/app.vue';
+import groupFolderComponent from './components/group_folder.vue';
+import groupItemComponent from './components/group_item.vue';
+
+Vue.use(Translate);
 
 document.addEventListener('DOMContentLoaded', () => {
-  const el = document.getElementById('dashboard-group-app');
+  const el = document.getElementById('js-groups-tree');
 
   // Don't do anything if element doesn't exist (No groups)
   // This is for when the user enters directly to the page via URL
@@ -18,176 +19,56 @@ document.addEventListener('DOMContentLoaded', () => {
     return;
   }
 
-  Vue.component('groups-component', GroupsComponent);
-  Vue.component('group-folder', GroupFolder);
-  Vue.component('group-item', GroupItem);
+  Vue.component('group-folder', groupFolderComponent);
+  Vue.component('group-item', groupItemComponent);
 
   // eslint-disable-next-line no-new
   new Vue({
     el,
+    components: {
+      groupsApp,
+    },
     data() {
-      this.store = new GroupsStore();
-      this.service = new GroupsService(el.dataset.endpoint);
+      const dataset = this.$options.el.dataset;
+      const hideProjects = dataset.hideProjects === 'true';
+      const store = new GroupsStore(hideProjects);
+      const service = new GroupsService(dataset.endpoint);
 
       return {
-        store: this.store,
-        isLoading: true,
-        state: this.store.state,
+        store,
+        service,
+        hideProjects,
         loading: true,
       };
     },
-    computed: {
-      isEmpty() {
-        return Object.keys(this.state.groups).length === 0;
-      },
-    },
-    methods: {
-      fetchGroups(parentGroup) {
-        let parentId = null;
-        let getGroups = null;
-        let page = null;
-        let sort = null;
-        let pageParam = null;
-        let sortParam = null;
-        let filterGroups = null;
-        let filterGroupsParam = null;
-
-        if (parentGroup) {
-          parentId = parentGroup.id;
-        } else {
-          this.isLoading = true;
-        }
-
-        pageParam = getParameterByName('page');
-        if (pageParam) {
-          page = pageParam;
-        }
-
-        filterGroupsParam = getParameterByName('filter_groups');
-        if (filterGroupsParam) {
-          filterGroups = filterGroupsParam;
-        }
-
-        sortParam = getParameterByName('sort');
-        if (sortParam) {
-          sort = sortParam;
-        }
-
-        getGroups = this.service.getGroups(parentId, page, filterGroups, sort);
-        getGroups
-          .then(response => response.json())
-          .then((response) => {
-            this.isLoading = false;
-
-            this.updateGroups(response, parentGroup);
-          })
-          .catch(this.handleErrorResponse);
-
-        return getGroups;
-      },
-      fetchPage(page, filterGroups, sort) {
-        this.isLoading = true;
-
-        return this.service
-          .getGroups(null, page, filterGroups, sort)
-          .then((response) => {
-            this.isLoading = false;
-            $.scrollTo(0);
-
-            const currentPath = gl.utils.mergeUrlParams({ page }, window.location.href);
-            window.history.replaceState({
-              page: currentPath,
-            }, document.title, currentPath);
-
-            return response.json().then((data) => {
-              this.updateGroups(data);
-              this.updatePagination(response.headers);
-            });
-          })
-          .catch(this.handleErrorResponse);
-      },
-      toggleSubGroups(parentGroup = null) {
-        if (!parentGroup.isOpen) {
-          this.store.resetGroups(parentGroup);
-          this.fetchGroups(parentGroup);
-        }
-
-        this.store.toggleSubGroups(parentGroup);
-      },
-      leaveGroup(group, collection) {
-        this.service.leaveGroup(group.leavePath)
-          .then(resp => resp.json())
-          .then((response) => {
-            $.scrollTo(0);
-
-            this.store.removeGroup(group, collection);
-
-            // eslint-disable-next-line no-new
-            new Flash(response.notice, 'notice');
-          })
-          .catch((error) => {
-            let message = 'An error occurred. Please try again.';
-
-            if (error.status === 403) {
-              message = 'Failed to leave the group. Please make sure you are not the only owner';
-            }
-
-            // eslint-disable-next-line no-new
-            new Flash(message);
-          });
-      },
-      updateGroups(groups, parentGroup) {
-        this.store.setGroups(groups, parentGroup);
-      },
-      updatePagination(headers) {
-        this.store.storePagination(headers);
-      },
-      handleErrorResponse() {
-        this.isLoading = false;
-        $.scrollTo(0);
-
-        // eslint-disable-next-line no-new
-        new Flash('An error occurred. Please try again.');
-      },
-    },
-    created() {
-      eventHub.$on('fetchPage', this.fetchPage);
-      eventHub.$on('toggleSubGroups', this.toggleSubGroups);
-      eventHub.$on('leaveGroup', this.leaveGroup);
-      eventHub.$on('updateGroups', this.updateGroups);
-      eventHub.$on('updatePagination', this.updatePagination);
-    },
     beforeMount() {
+      const dataset = this.$options.el.dataset;
       let groupFilterList = null;
-      const form = document.querySelector('form#group-filter-form');
-      const filter = document.querySelector('.js-groups-list-filter');
-      const holder = document.querySelector('.js-groups-list-holder');
+      const form = document.querySelector(dataset.formSel);
+      const filter = document.querySelector(dataset.filterSel);
+      const holder = document.querySelector(dataset.holderSel);
 
       const opts = {
         form,
         filter,
         holder,
-        filterEndpoint: el.dataset.endpoint,
-        pagePath: el.dataset.path,
+        filterEndpoint: dataset.endpoint,
+        pagePath: dataset.path,
+        dropdownSel: dataset.dropdownSel,
+        filterInputField: 'filter',
       };
 
       groupFilterList = new GroupFilterableList(opts);
       groupFilterList.initSearch();
     },
-    mounted() {
-      this.fetchGroups()
-        .then((response) => {
-          this.updatePagination(response.headers);
-          this.isLoading = false;
-        })
-        .catch(this.handleErrorResponse);
-    },
-    beforeDestroy() {
-      eventHub.$off('fetchPage', this.fetchPage);
-      eventHub.$off('toggleSubGroups', this.toggleSubGroups);
-      eventHub.$off('leaveGroup', this.leaveGroup);
-      eventHub.$off('updateGroups', this.updateGroups);
-      eventHub.$off('updatePagination', this.updatePagination);
+    render(createElement) {
+      return createElement('groups-app', {
+        props: {
+          store: this.store,
+          service: this.service,
+          hideProjects: this.hideProjects,
+        },
+      });
     },
   });
 });
diff --git a/app/assets/javascripts/groups/new_group_child.js b/app/assets/javascripts/groups/new_group_child.js
new file mode 100644
index 00000000000..8e273579aae
--- /dev/null
+++ b/app/assets/javascripts/groups/new_group_child.js
@@ -0,0 +1,62 @@
+import DropLab from '../droplab/drop_lab';
+import ISetter from '../droplab/plugins/input_setter';
+
+const InputSetter = Object.assign({}, ISetter);
+
+const NEW_PROJECT = 'new-project';
+const NEW_SUBGROUP = 'new-subgroup';
+
+export default class NewGroupChild {
+  constructor(buttonWrapper) {
+    this.buttonWrapper = buttonWrapper;
+    this.newGroupChildButton = this.buttonWrapper.querySelector('.js-new-group-child');
+    this.dropdownToggle = this.buttonWrapper.querySelector('.js-dropdown-toggle');
+    this.dropdownList = this.buttonWrapper.querySelector('.dropdown-menu');
+
+    this.newGroupPath = this.buttonWrapper.dataset.projectPath;
+    this.subgroupPath = this.buttonWrapper.dataset.subgroupPath;
+
+    this.init();
+  }
+
+  init() {
+    this.initDroplab();
+    this.bindEvents();
+  }
+
+  initDroplab() {
+    this.droplab = new DropLab();
+    this.droplab.init(
+      this.dropdownToggle,
+      this.dropdownList,
+      [InputSetter],
+      this.getDroplabConfig(),
+    );
+  }
+
+  getDroplabConfig() {
+    return {
+      InputSetter: [{
+        input: this.newGroupChildButton,
+        valueAttribute: 'data-value',
+        inputAttribute: 'data-action',
+      }, {
+        input: this.newGroupChildButton,
+        valueAttribute: 'data-text',
+      }],
+    };
+  }
+
+  bindEvents() {
+    this.newGroupChildButton
+      .addEventListener('click', this.onClickNewGroupChildButton.bind(this));
+  }
+
+  onClickNewGroupChildButton(e) {
+    if (e.target.dataset.action === NEW_PROJECT) {
+      gl.utils.visitUrl(this.newGroupPath);
+    } else if (e.target.dataset.action === NEW_SUBGROUP) {
+      gl.utils.visitUrl(this.subgroupPath);
+    }
+  }
+}
diff --git a/app/assets/javascripts/groups/services/groups_service.js b/app/assets/javascripts/groups/service/groups_service.js
index 97e02fcb76d..639410384c2 100644
--- a/app/assets/javascripts/groups/services/groups_service.js
+++ b/app/assets/javascripts/groups/service/groups_service.js
@@ -8,7 +8,7 @@ export default class GroupsService {
     this.groups = Vue.resource(endpoint);
   }
 
-  getGroups(parentId, page, filterGroups, sort) {
+  getGroups(parentId, page, filterGroups, sort, archived) {
     const data = {};
 
     if (parentId) {
@@ -20,12 +20,16 @@ export default class GroupsService {
       }
 
       if (filterGroups) {
-        data.filter_groups = filterGroups;
+        data.filter = filterGroups;
       }
 
       if (sort) {
         data.sort = sort;
       }
+
+      if (archived) {
+        data.archived = archived;
+      }
     }
 
     return this.groups.get(data);
diff --git a/app/assets/javascripts/groups/store/groups_store.js b/app/assets/javascripts/groups/store/groups_store.js
new file mode 100644
index 00000000000..a1689f4c5cc
--- /dev/null
+++ b/app/assets/javascripts/groups/store/groups_store.js
@@ -0,0 +1,105 @@
+import { normalizeHeaders, parseIntPagination } from '../../lib/utils/common_utils';
+
+export default class GroupsStore {
+  constructor(hideProjects) {
+    this.state = {};
+    this.state.groups = [];
+    this.state.pageInfo = {};
+    this.hideProjects = hideProjects;
+  }
+
+  setGroups(rawGroups) {
+    if (rawGroups && rawGroups.length) {
+      this.state.groups = rawGroups.map(rawGroup => this.formatGroupItem(rawGroup));
+    } else {
+      this.state.groups = [];
+    }
+  }
+
+  setSearchedGroups(rawGroups) {
+    const formatGroups = groups => groups.map((group) => {
+      const formattedGroup = this.formatGroupItem(group);
+      if (formattedGroup.children && formattedGroup.children.length) {
+        formattedGroup.children = formatGroups(formattedGroup.children);
+      }
+      return formattedGroup;
+    });
+
+    if (rawGroups && rawGroups.length) {
+      this.state.groups = formatGroups(rawGroups);
+    } else {
+      this.state.groups = [];
+    }
+  }
+
+  setGroupChildren(parentGroup, children) {
+    const updatedParentGroup = parentGroup;
+    updatedParentGroup.children = children.map(rawChild => this.formatGroupItem(rawChild));
+    updatedParentGroup.isOpen = true;
+    updatedParentGroup.isChildrenLoading = false;
+  }
+
+  getGroups() {
+    return this.state.groups;
+  }
+
+  setPaginationInfo(pagination = {}) {
+    let paginationInfo;
+
+    if (Object.keys(pagination).length) {
+      const normalizedHeaders = normalizeHeaders(pagination);
+      paginationInfo = parseIntPagination(normalizedHeaders);
+    } else {
+      paginationInfo = pagination;
+    }
+
+    this.state.pageInfo = paginationInfo;
+  }
+
+  getPaginationInfo() {
+    return this.state.pageInfo;
+  }
+
+  formatGroupItem(rawGroupItem) {
+    const groupChildren = rawGroupItem.children || [];
+    const groupIsOpen = (groupChildren.length > 0) || false;
+    const childrenCount = this.hideProjects ?
+      rawGroupItem.subgroup_count :
+      rawGroupItem.children_count;
+
+    return {
+      id: rawGroupItem.id,
+      name: rawGroupItem.name,
+      fullName: rawGroupItem.full_name,
+      description: rawGroupItem.description,
+      visibility: rawGroupItem.visibility,
+      avatarUrl: rawGroupItem.avatar_url,
+      relativePath: rawGroupItem.relative_path,
+      editPath: rawGroupItem.edit_path,
+      leavePath: rawGroupItem.leave_path,
+      canEdit: rawGroupItem.can_edit,
+      canLeave: rawGroupItem.can_leave,
+      type: rawGroupItem.type,
+      permission: rawGroupItem.permission,
+      children: groupChildren,
+      isOpen: groupIsOpen,
+      isChildrenLoading: false,
+      isBeingRemoved: false,
+      parentId: rawGroupItem.parent_id,
+      childrenCount,
+      projectCount: rawGroupItem.project_count,
+      subgroupCount: rawGroupItem.subgroup_count,
+      memberCount: rawGroupItem.number_users_with_delimiter,
+      starCount: rawGroupItem.star_count,
+    };
+  }
+
+  removeGroup(group, parentGroup) {
+    const updatedParentGroup = parentGroup;
+    if (updatedParentGroup.children && updatedParentGroup.children.length) {
+      updatedParentGroup.children = parentGroup.children.filter(child => group.id !== child.id);
+    } else {
+      this.state.groups = this.state.groups.filter(child => group.id !== child.id);
+    }
+  }
+}
diff --git a/app/assets/javascripts/groups/stores/groups_store.js b/app/assets/javascripts/groups/stores/groups_store.js
deleted file mode 100644
index f59ec677603..00000000000
--- a/app/assets/javascripts/groups/stores/groups_store.js
+++ /dev/null
@@ -1,167 +0,0 @@
-import Vue from 'vue';
-import { parseIntPagination, normalizeHeaders } from '../../lib/utils/common_utils';
-
-export default class GroupsStore {
-  constructor() {
-    this.state = {};
-    this.state.groups = {};
-    this.state.pageInfo = {};
-  }
-
-  setGroups(rawGroups, parent) {
-    const parentGroup = parent;
-    const tree = this.buildTree(rawGroups, parentGroup);
-
-    if (parentGroup) {
-      parentGroup.subGroups = tree;
-    } else {
-      this.state.groups = tree;
-    }
-
-    return tree;
-  }
-
-  // eslint-disable-next-line class-methods-use-this
-  resetGroups(parent) {
-    const parentGroup = parent;
-    parentGroup.subGroups = {};
-  }
-
-  storePagination(pagination = {}) {
-    let paginationInfo;
-
-    if (Object.keys(pagination).length) {
-      const normalizedHeaders = normalizeHeaders(pagination);
-      paginationInfo = parseIntPagination(normalizedHeaders);
-    } else {
-      paginationInfo = pagination;
-    }
-
-    this.state.pageInfo = paginationInfo;
-  }
-
-  buildTree(rawGroups, parentGroup) {
-    const groups = this.decorateGroups(rawGroups);
-    const tree = {};
-    const mappedGroups = {};
-    const orphans = [];
-
-    // Map groups to an object
-    groups.map((group) => {
-      mappedGroups[`id${group.id}`] = group;
-      mappedGroups[`id${group.id}`].subGroups = {};
-      return group;
-    });
-
-    Object.keys(mappedGroups).map((key) => {
-      const currentGroup = mappedGroups[key];
-      if (currentGroup.parentId) {
-        // If the group is not at the root level, add it to its parent array of subGroups.
-        const findParentGroup = mappedGroups[`id${currentGroup.parentId}`];
-        if (findParentGroup) {
-          mappedGroups[`id${currentGroup.parentId}`].subGroups[`id${currentGroup.id}`] = currentGroup;
-          mappedGroups[`id${currentGroup.parentId}`].isOpen = true; // Expand group if it has subgroups
-        } else if (parentGroup && parentGroup.id === currentGroup.parentId) {
-          tree[`id${currentGroup.id}`] = currentGroup;
-        } else {
-          // No parent found. We save it for later processing
-          orphans.push(currentGroup);
-
-          // Add to tree to preserve original order
-          tree[`id${currentGroup.id}`] = currentGroup;
-        }
-      } else {
-        // If the group is at the top level, add it to first level elements array.
-        tree[`id${currentGroup.id}`] = currentGroup;
-      }
-
-      return key;
-    });
-
-    if (orphans.length) {
-      orphans.map((orphan) => {
-        let found = false;
-        const currentOrphan = orphan;
-
-        Object.keys(tree).map((key) => {
-          const group = tree[key];
-
-          if (
-           group &&
-           currentOrphan.fullPath.lastIndexOf(group.fullPath) === 0 &&
-           // Make sure the currently selected orphan is not the same as the group
-           // we are checking here otherwise it will end up in an infinite loop
-           currentOrphan.id !== group.id
-           ) {
-            group.subGroups[currentOrphan.id] = currentOrphan;
-            group.isOpen = true;
-            currentOrphan.isOrphan = true;
-            found = true;
-
-            // Delete if group was put at the top level. If not the group will be displayed twice.
-            if (tree[`id${currentOrphan.id}`]) {
-              delete tree[`id${currentOrphan.id}`];
-            }
-          }
-
-          return key;
-        });
-
-        if (!found) {
-          currentOrphan.isOrphan = true;
-
-          tree[`id${currentOrphan.id}`] = currentOrphan;
-        }
-
-        return orphan;
-      });
-    }
-
-    return tree;
-  }
-
-  decorateGroups(rawGroups) {
-    this.groups = rawGroups.map(this.decorateGroup);
-    return this.groups;
-  }
-
-  // eslint-disable-next-line class-methods-use-this
-  decorateGroup(rawGroup) {
-    return {
-      id: rawGroup.id,
-      fullName: rawGroup.full_name,
-      fullPath: rawGroup.full_path,
-      avatarUrl: rawGroup.avatar_url,
-      name: rawGroup.name,
-      hasSubgroups: rawGroup.has_subgroups,
-      canEdit: rawGroup.can_edit,
-      description: rawGroup.description,
-      webUrl: rawGroup.web_url,
-      groupPath: rawGroup.group_path,
-      parentId: rawGroup.parent_id,
-      visibility: rawGroup.visibility,
-      leavePath: rawGroup.leave_path,
-      editPath: rawGroup.edit_path,
-      isOpen: false,
-      isOrphan: false,
-      numberProjects: rawGroup.number_projects_with_delimiter,
-      numberUsers: rawGroup.number_users_with_delimiter,
-      permissions: {
-        humanGroupAccess: rawGroup.permissions.human_group_access,
-      },
-      subGroups: {},
-    };
-  }
-
-  // eslint-disable-next-line class-methods-use-this
-  removeGroup(group, collection) {
-    Vue.delete(collection, `id${group.id}`);
-  }
-
-  // eslint-disable-next-line class-methods-use-this
-  toggleSubGroups(toggleGroup) {
-    const group = toggleGroup;
-    group.isOpen = !group.isOpen;
-    return group;
-  }
-}
diff --git a/app/assets/stylesheets/framework/lists.scss b/app/assets/stylesheets/framework/lists.scss
index badc7b0eba3..d43f998cb82 100644
--- a/app/assets/stylesheets/framework/lists.scss
+++ b/app/assets/stylesheets/framework/lists.scss
@@ -281,6 +281,57 @@ ul.indent-list {
 
 
 // Specific styles for tree list
+@keyframes spin-avatar {
+  from { transform: rotate(0deg); }
+  to { transform: rotate(360deg); }
+}
+
+.groups-list-tree-container {
+  .has-no-search-results {
+    text-align: center;
+    padding: $gl-padding;
+    font-style: italic;
+    color: $well-light-text-color;
+  }
+
+  > .group-list-tree > .group-row.has-children:first-child {
+    border-top: none;
+  }
+}
+
+.group-list-tree .avatar-container.content-loading {
+  position: relative;
+
+  > a,
+  > a .avatar {
+    height: 100%;
+    border-radius: 50%;
+  }
+
+  > a {
+    padding: 2px;
+  }
+
+  > a .avatar {
+    border: 2px solid $white-normal;
+
+    &.identicon {
+      line-height: 30px;
+    }
+  }
+
+  &::after {
+    content: "";
+    position: absolute;
+    height: 100%;
+    width: 100%;
+    background-color: transparent;
+    border: 2px outset $kdb-border;
+    border-radius: 50%;
+    animation: spin-avatar 3s infinite linear;
+  }
+}
+
 .group-list-tree {
   .folder-toggle-wrap {
     float: left;
@@ -293,7 +344,7 @@ ul.indent-list {
   }
 
   .folder-caret,
-  .folder-icon {
+  .item-type-icon {
     display: inline-block;
   }
 
@@ -301,11 +352,11 @@ ul.indent-list {
     width: 15px;
   }
 
-  .folder-icon {
+  .item-type-icon {
     width: 20px;
   }
 
-  > .group-row:not(.has-subgroups) {
+  > .group-row:not(.has-children) {
     .folder-caret .fa {
       opacity: 0;
     }
@@ -351,12 +402,23 @@ ul.indent-list {
         top: 30px;
         bottom: 0;
       }
+
+      &.being-removed {
+        opacity: 0.5;
+      }
     }
   }
 
   .group-row {
     padding: 0;
-    border: none;
+
+    &.has-children {
+      border-top: none;
+    }
+
+    &:first-child {
+      border-top: 1px solid $white-normal;
+    }
 
     &:last-of-type {
       .group-row-contents:not(:hover) {
@@ -379,6 +441,25 @@ ul.indent-list {
     .avatar-container > a {
       width: 100%;
     }
+
+    &.has-more-items {
+      display: block;
+      padding: 20px 10px;
+    }
+  }
+}
+
+ul.group-list-tree {
+  li.group-row {
+    &.has-description {
+      .title {
+        line-height: inherit;
+      }
+    }
+
+    .title {
+      line-height: $list-text-height;
+    }
   }
 }
 
diff --git a/app/assets/stylesheets/pages/groups.scss b/app/assets/stylesheets/pages/groups.scss
index 6f6c6839975..9b7dda9b648 100644
--- a/app/assets/stylesheets/pages/groups.scss
+++ b/app/assets/stylesheets/pages/groups.scss
@@ -26,14 +26,117 @@
   }
 }
 
-.groups-header {
-  @media (min-width: $screen-sm-min) {
-    .nav-links {
-      width: 35%;
+.group-nav-container .nav-controls {
+  display: flex;
+  align-items: flex-start;
+  padding: $gl-padding-top 0;
+  border-bottom: 1px solid $border-color;
+
+  .group-filter-form {
+    flex: 1;
+  }
+
+  .dropdown-menu-align-right {
+    margin-top: 0;
+  }
+
+  .new-project-subgroup {
+    .dropdown-primary {
+      min-width: 115px;
+    }
+
+    .dropdown-toggle {
+      .dropdown-btn-icon {
+        pointer-events: none;
+        color: inherit;
+        margin-left: 0;
+      }
     }
 
-    .nav-controls {
-      width: 65%;
+    .dropdown-menu {
+      min-width: 280px;
+      margin-top: 2px;
+    }
+
+    li:not(.divider) {
+      padding: 0;
+
+      &.droplab-item-selected {
+        .icon-container {
+          .list-item-checkmark {
+            visibility: visible;
+          }
+        }
+      }
+
+      .menu-item {
+        padding: 8px 4px;
+
+        &:hover {
+          background-color: $gray-darker;
+          color: $theme-gray-900;
+        }
+      }
+
+      .icon-container {
+        float: left;
+        padding-left: 6px;
+
+        .list-item-checkmark {
+          visibility: hidden;
+        }
+      }
+
+      .description {
+        font-size: 14px;
+
+        strong {
+          display: block;
+          font-weight: $gl-font-weight-bold;
+        }
+      }
+    }
+  }
+
+  @media (max-width: $screen-sm-max) {
+    &,
+    .dropdown,
+    .dropdown .dropdown-toggle,
+    .btn-new {
+      display: block;
+    }
+
+    .group-filter-form,
+    .dropdown {
+      margin-bottom: 10px;
+      margin-right: 0;
+    }
+
+    .group-filter-form,
+    .dropdown .dropdown-toggle,
+    .btn-new {
+      width: 100%;
+    }
+
+    .dropdown .dropdown-toggle .fa-chevron-down {
+      position: absolute;
+      top: 11px;
+      right: 8px;
+    }
+
+    .new-project-subgroup {
+      display: flex;
+      align-items: flex-start;
+
+      .dropdown-primary {
+        flex: 1;
+      }
+
+      .dropdown-menu {
+        width: 100%;
+        max-width: inherit;
+        min-width: inherit;
+      }
     }
   }
 }
diff --git a/app/controllers/concerns/group_tree.rb b/app/controllers/concerns/group_tree.rb
new file mode 100644
index 00000000000..9d4f97aa443
--- /dev/null
+++ b/app/controllers/concerns/group_tree.rb
@@ -0,0 +1,24 @@
+module GroupTree
+  def render_group_tree(groups)
+    @groups = if params[:filter].present?
+                Gitlab::GroupHierarchy.new(groups.search(params[:filter]))
+                  .base_and_ancestors
+              else
+                # Only show root groups if no parent-id is given
+                groups.where(parent_id: params[:parent_id])
+              end
+    @groups = @groups.with_selects_for_list(archived: params[:archived])
+                .sort(@sort = params[:sort])
+                .page(params[:page])
+
+    respond_to do |format|
+      format.html
+      format.json do
+        serializer = GroupChildSerializer.new(current_user: current_user)
+                       .with_pagination(request, response)
+        serializer.expand_hierarchy if params[:filter].present?
+        render json: serializer.represent(@groups)
+      end
+    end
+  end
+end
diff --git a/app/controllers/dashboard/groups_controller.rb b/app/controllers/dashboard/groups_controller.rb
index 7ed18fb481c..025769f512a 100644
--- a/app/controllers/dashboard/groups_controller.rb
+++ b/app/controllers/dashboard/groups_controller.rb
@@ -1,33 +1,8 @@
 class Dashboard::GroupsController < Dashboard::ApplicationController
-  def index
-    @sort = params[:sort] || 'created_desc'
-
-    @groups =
-      if params[:parent_id] && Group.supports_nested_groups?
-        parent = Group.find_by(id: params[:parent_id])
-
-        if can?(current_user, :read_group, parent)
-          GroupsFinder.new(current_user, parent: parent).execute
-        else
-          Group.none
-        end
-      else
-        current_user.groups
-      end
+  include GroupTree
 
-    @groups = @groups.search(params[:filter_groups]) if params[:filter_groups].present?
-    @groups = @groups.includes(:route)
-    @groups = @groups.sort(@sort)
-    @groups = @groups.page(params[:page])
-
-    respond_to do |format|
-      format.html
-      format.json do
-        render json: GroupSerializer
-          .new(current_user: @current_user)
-          .with_pagination(request, response)
-          .represent(@groups)
-      end
-    end
+  def index
+    groups = GroupsFinder.new(current_user, all_available: false).execute
+    render_group_tree(groups)
   end
 end
diff --git a/app/controllers/explore/groups_controller.rb b/app/controllers/explore/groups_controller.rb
index 81883c543ba..fa0a0f68fbc 100644
--- a/app/controllers/explore/groups_controller.rb
+++ b/app/controllers/explore/groups_controller.rb
@@ -1,17 +1,7 @@
 class Explore::GroupsController < Explore::ApplicationController
-  def index
-    @groups = GroupsFinder.new(current_user).execute
-    @groups = @groups.search(params[:filter_groups]) if params[:filter_groups].present?
-    @groups = @groups.sort(@sort = params[:sort])
-    @groups = @groups.page(params[:page])
+  include GroupTree
 
-    respond_to do |format|
-      format.html
-      format.json do
-        render json: {
-          html: view_to_html_string("explore/groups/_groups", locals: { groups: @groups })
-        }
-      end
-    end
+  def index
+    render_group_tree GroupsFinder.new(current_user).execute
   end
 end
diff --git a/app/controllers/groups/children_controller.rb b/app/controllers/groups/children_controller.rb
new file mode 100644
index 00000000000..b474f5d15ee
--- /dev/null
+++ b/app/controllers/groups/children_controller.rb
@@ -0,0 +1,39 @@
+module Groups
+  class ChildrenController < Groups::ApplicationController
+    before_action :group
+
+    def index
+      parent = if params[:parent_id].present?
+                 GroupFinder.new(current_user).execute(id: params[:parent_id])
+               else
+                 @group
+               end
+
+      if parent.nil?
+        render_404
+        return
+      end
+
+      setup_children(parent)
+
+      respond_to do |format|
+        format.json do
+          serializer = GroupChildSerializer
+                         .new(current_user: current_user)
+                         .with_pagination(request, response)
+          serializer.expand_hierarchy(parent) if params[:filter].present?
+          render json: serializer.represent(@children)
+        end
+      end
+    end
+
+    protected
+
+    def setup_children(parent)
+      @children = GroupDescendantsFinder.new(current_user: current_user,
+                                             parent_group: parent,
+                                             params: params).execute
+      @children = @children.page(params[:page])
+    end
+  end
+end
diff --git a/app/controllers/groups_controller.rb b/app/controllers/groups_controller.rb
index a962d82e3b5..e23a82d01be 100644
--- a/app/controllers/groups_controller.rb
+++ b/app/controllers/groups_controller.rb
@@ -46,15 +46,11 @@ class GroupsController < Groups::ApplicationController
   end
 
   def show
-    setup_projects
-
     respond_to do |format|
-      format.html
-
-      format.json do
-        render json: {
-          html: view_to_html_string("dashboard/projects/_projects", locals: { projects: @projects })
-        }
+      format.html do
+        @has_children = GroupDescendantsFinder.new(current_user: current_user,
+                                                   parent_group: @group,
+                                                   params: params).has_children?
       end
 
       format.atom do
@@ -64,13 +60,6 @@ class GroupsController < Groups::ApplicationController
     end
   end
 
-  def subgroups
-    return not_found unless Group.supports_nested_groups?
-
-    @nested_groups = GroupsFinder.new(current_user, parent: group).execute
-    @nested_groups = @nested_groups.search(params[:filter_groups]) if params[:filter_groups].present?
-  end
-
   def activity
     respond_to do |format|
       format.html
@@ -107,20 +96,6 @@ class GroupsController < Groups::ApplicationController
 
   protected
 
-  def setup_projects
-    set_non_archived_param
-    params[:sort] ||= 'latest_activity_desc'
-    @sort = params[:sort]
-
-    options = {}
-    options[:only_owned] = true if params[:shared] == '0'
-    options[:only_shared] = true if params[:shared] == '1'
-
-    @projects = GroupProjectsFinder.new(params: params, group: group, options: options, current_user: current_user).execute
-    @projects = @projects.includes(:namespace)
-    @projects = @projects.page(params[:page]) if params[:name].blank?
-  end
-
   def authorize_create_group!
     allowed = if params[:parent_id].present?
                 parent = Group.find_by(id: params[:parent_id])
diff --git a/app/finders/group_descendants_finder.rb b/app/finders/group_descendants_finder.rb
new file mode 100644
index 00000000000..1a5f6063437
--- /dev/null
+++ b/app/finders/group_descendants_finder.rb
@@ -0,0 +1,153 @@
+# GroupDescendantsFinder
+#
+# Used to find and filter all subgroups and projects of a passed parent group
+# visible to a specified user.
+#
+# When passing a `filter` param, the search is performed over all nested levels
+# of the `parent_group`. All ancestors for a search result are loaded
+#
+# Arguments:
+#   current_user: The user for which the children should be visible
+#   parent_group: The group to find children of
+#   params:
+#     Supports all params that the `ProjectsFinder` and `GroupProjectsFinder`
+#     support.
+#
+#     filter: string - is aliased to `search` for consistency with the frontend
+#     archived: string - `only` or `true`.
+#                        `non_archived` is passed to the `ProjectFinder`s if none
+#                        was given.
+class GroupDescendantsFinder
+  attr_reader :current_user, :parent_group, :params
+
+  def initialize(current_user: nil, parent_group:, params: {})
+    @current_user = current_user
+    @parent_group = parent_group
+    @params = params.reverse_merge(non_archived: params[:archived].blank?)
+  end
+
+  def execute
+    # The children array might be extended with the ancestors of projects when
+    # filtering. In that case, take the maximum so the array does not get limited
+    # Otherwise, allow paginating through all results
+    #
+    all_required_elements = children
+    all_required_elements |= ancestors_for_projects if params[:filter]
+    total_count = [all_required_elements.size, paginator.total_count].max
+
+    Kaminari.paginate_array(all_required_elements, total_count: total_count)
+  end
+
+  def has_children?
+    projects.any? || subgroups.any?
+  end
+
+  private
+
+  def children
+    @children ||= paginator.paginate(params[:page])
+  end
+
+  def paginator
+    @paginator ||= Gitlab::MultiCollectionPaginator.new(subgroups, projects,
+                                                        per_page: params[:per_page])
+  end
+
+  def direct_child_groups
+    GroupsFinder.new(current_user,
+                     parent: parent_group,
+                     all_available: true).execute
+  end
+
+  def all_visible_descendant_groups
+    groups_table = Group.arel_table
+    visible_to_user = groups_table[:visibility_level]
+                      .in(Gitlab::VisibilityLevel.levels_for_user(current_user))
+    if current_user
+      authorized_groups = GroupsFinder.new(current_user,
+                                           all_available: false)
+                            .execute.as('authorized')
+      authorized_to_user = groups_table.project(1).from(authorized_groups)
+                             .where(authorized_groups[:id].eq(groups_table[:id]))
+                             .exists
+      visible_to_user = visible_to_user.or(authorized_to_user)
+    end
+
+    hierarchy_for_parent
+      .descendants
+      .where(visible_to_user)
+  end
+
+  def subgroups_matching_filter
+    all_visible_descendant_groups
+      .search(params[:filter])
+  end
+
+  # When filtering we want all to preload all the ancestors upto the specified
+  # parent group.
+  #
+  # - root
+  #   - subgroup
+  #     - nested-group
+  #       - project
+  #
+  # So when searching 'project', on the 'subgroup' page we want to preload
+  # 'nested-group' but not 'subgroup' or 'root'
+  def ancestors_for_groups(base_for_ancestors)
+    Gitlab::GroupHierarchy.new(base_for_ancestors)
+      .base_and_ancestors(upto: parent_group.id)
+  end
+
+  def ancestors_for_projects
+    projects_to_load_ancestors_of = projects.where.not(namespace: parent_group)
+    groups_to_load_ancestors_of = Group.where(id: projects_to_load_ancestors_of.select(:namespace_id))
+    ancestors_for_groups(groups_to_load_ancestors_of)
+      .with_selects_for_list(archived: params[:archived])
+  end
+
+  def subgroups
+    return Group.none unless Group.supports_nested_groups?
+
+    # When filtering subgroups, we want to find all matches withing the tree of
+    # descendants to show to the user
+    groups = if params[:filter]
+               ancestors_for_groups(subgroups_matching_filter)
+             else
+               direct_child_groups
+             end
+    groups.with_selects_for_list(archived: params[:archived]).order_by(sort)
+  end
+
+  def direct_child_projects
+    GroupProjectsFinder.new(group: parent_group, current_user: current_user, params: params)
+      .execute
+  end
+
+  # Finds all projects nested under `parent_group` or any of its descendant
+  # groups
+  def projects_matching_filter
+    projects_nested_in_group = Project.where(namespace_id: hierarchy_for_parent.base_and_descendants.select(:id))
+    params_with_search = params.merge(search: params[:filter])
+
+    ProjectsFinder.new(params: params_with_search,
+                       current_user: current_user,
+                       project_ids_relation: projects_nested_in_group).execute
+  end
+
+  def projects
+    projects = if params[:filter]
+                 projects_matching_filter
+               else
+                 direct_child_projects
+               end
+    projects.with_route.order_by(sort)
+  end
+
+  def sort
+    params.fetch(:sort, 'id_asc')
+  end
+
+  def hierarchy_for_parent
+    @hierarchy ||= Gitlab::GroupHierarchy.new(Group.where(id: parent_group.id))
+  end
+end
diff --git a/app/finders/group_projects_finder.rb b/app/finders/group_projects_finder.rb
index f2d3b90b8e2..6e8733bb49c 100644
--- a/app/finders/group_projects_finder.rb
+++ b/app/finders/group_projects_finder.rb
@@ -34,7 +34,6 @@ class GroupProjectsFinder < ProjectsFinder
                else
                  collection_without_user
                end
-
     union(projects)
   end
 
diff --git a/app/helpers/sorting_helper.rb b/app/helpers/sorting_helper.rb
index 1b542ed2a96..b05eb93b465 100644
--- a/app/helpers/sorting_helper.rb
+++ b/app/helpers/sorting_helper.rb
@@ -42,6 +42,17 @@ module SortingHelper
     options
   end
 
+  def groups_sort_options_hash
+    options = {
+      sort_value_recently_created => sort_title_recently_created,
+      sort_value_oldest_created => sort_title_oldest_created,
+      sort_value_recently_updated => sort_title_recently_updated,
+      sort_value_oldest_updated => sort_title_oldest_updated
+    }
+
+    options
+  end
+
   def member_sort_options_hash
     {
       sort_value_access_level_asc  => sort_title_access_level_asc,
diff --git a/app/models/concerns/group_descendant.rb b/app/models/concerns/group_descendant.rb
new file mode 100644
index 00000000000..01957da0bf3
--- /dev/null
+++ b/app/models/concerns/group_descendant.rb
@@ -0,0 +1,56 @@
+module GroupDescendant
+  # Returns the hierarchy of a project or group in the from of a hash upto a
+  # given top.
+  #
+  # > project.hierarchy
+  # => { parent_group => { child_group => project } }
+  def hierarchy(hierarchy_top = nil, preloaded = nil)
+    preloaded ||= ancestors_upto(hierarchy_top)
+    expand_hierarchy_for_child(self, self, hierarchy_top, preloaded)
+  end
+
+  # Merges all hierarchies of the given groups or projects into an array of
+  # hashes. All ancestors need to be loaded into the given `descendants` to avoid
+  # queries down the line.
+  #
+  # > GroupDescendant.merge_hierarchy([project, child_group, child_group2, parent])
+  # => { parent => [{ child_group => project}, child_group2] }
+  def self.build_hierarchy(descendants, hierarchy_top = nil)
+    descendants = Array.wrap(descendants).uniq
+    return [] if descendants.empty?
+
+    unless descendants.all? { |hierarchy| hierarchy.is_a?(GroupDescendant) }
+      raise ArgumentError.new('element is not a hierarchy')
+    end
+
+    all_hierarchies = descendants.map do |descendant|
+      descendant.hierarchy(hierarchy_top, descendants)
+    end
+
+    Gitlab::Utils::MergeHash.merge(all_hierarchies)
+  end
+
+  private
+
+  def expand_hierarchy_for_child(child, hierarchy, hierarchy_top, preloaded)
+    parent = hierarchy_top if hierarchy_top && child.parent_id == hierarchy_top.id
+    parent ||= preloaded.detect { |possible_parent| possible_parent.is_a?(Group) && possible_parent.id == child.parent_id }
+
+    if parent.nil? && !child.parent_id.nil?
+      raise ArgumentError.new('parent was not preloaded')
+    end
+
+    if parent.nil? && hierarchy_top.present?
+      raise ArgumentError.new('specified top is not part of the tree')
+    end
+
+    if parent && parent != hierarchy_top
+      expand_hierarchy_for_child(parent,
+                                 { parent => hierarchy },
+                                 hierarchy_top,
+                                 preloaded)
+    else
+      hierarchy
+    end
+  end
+end
diff --git a/app/models/concerns/loaded_in_group_list.rb b/app/models/concerns/loaded_in_group_list.rb
new file mode 100644
index 00000000000..dcb3b2b5ff3
--- /dev/null
+++ b/app/models/concerns/loaded_in_group_list.rb
@@ -0,0 +1,72 @@
+module LoadedInGroupList
+  extend ActiveSupport::Concern
+
+  module ClassMethods
+    def with_counts(archived:)
+      selects_including_counts = [
+        'namespaces.*',
+        "(#{project_count_sql(archived).to_sql}) AS preloaded_project_count",
+        "(#{member_count_sql.to_sql}) AS preloaded_member_count",
+        "(#{subgroup_count_sql.to_sql}) AS preloaded_subgroup_count"
+      ]
+
+      select(selects_including_counts)
+    end
+
+    def with_selects_for_list(archived: nil)
+      with_route.with_counts(archived: archived)
+    end
+
+    private
+
+    def project_count_sql(archived = nil)
+      projects = Project.arel_table
+      namespaces = Namespace.arel_table
+
+      base_count = projects.project(Arel.star.count.as('preloaded_project_count'))
+                     .where(projects[:namespace_id].eq(namespaces[:id]))
+      if archived == 'only'
+        base_count.where(projects[:archived].eq(true))
+      elsif Gitlab::Utils.to_boolean(archived)
+        base_count
+      else
+        base_count.where(projects[:archived].not_eq(true))
+      end
+    end
+
+    def subgroup_count_sql
+      namespaces = Namespace.arel_table
+      children = namespaces.alias('children')
+
+      namespaces.project(Arel.star.count.as('preloaded_subgroup_count'))
+        .from(children)
+        .where(children[:parent_id].eq(namespaces[:id]))
+    end
+
+    def member_count_sql
+      members = Member.arel_table
+      namespaces = Namespace.arel_table
+
+      members.project(Arel.star.count.as('preloaded_member_count'))
+        .where(members[:source_type].eq(Namespace.name))
+        .where(members[:source_id].eq(namespaces[:id]))
+        .where(members[:requested_at].eq(nil))
+    end
+  end
+
+  def children_count
+    @children_count ||= project_count + subgroup_count
+  end
+
+  def project_count
+    @project_count ||= try(:preloaded_project_count) || projects.non_archived.count
+  end
+
+  def subgroup_count
+    @subgroup_count ||= try(:preloaded_subgroup_count) || children.count
+  end
+
+  def member_count
+    @member_count ||= try(:preloaded_member_count) || users.count
+  end
+end
diff --git a/app/models/group.rb b/app/models/group.rb
index e746e4a12c9..07fb62bb249 100644
--- a/app/models/group.rb
+++ b/app/models/group.rb
@@ -6,6 +6,8 @@ class Group < Namespace
   include Avatarable
   include Referable
   include SelectForProjectAuthorization
+  include LoadedInGroupList
+  include GroupDescendant
 
   has_many :group_members, -> { where(requested_at: nil) }, dependent: :destroy, as: :source # rubocop:disable Cop/ActiveRecordDependent
   alias_method :members, :group_members
diff --git a/app/models/namespace.rb b/app/models/namespace.rb
index 4672881e220..0601a61a926 100644
--- a/app/models/namespace.rb
+++ b/app/models/namespace.rb
@@ -162,6 +162,13 @@ class Namespace < ActiveRecord::Base
       .base_and_ancestors
   end
 
+  # returns all ancestors upto but excluding the the given namespace
+  # when no namespace is given, all ancestors upto the top are returned
+  def ancestors_upto(top = nil)
+    Gitlab::GroupHierarchy.new(self.class.where(id: id))
+      .ancestors(upto: top)
+  end
+
   def self_and_ancestors
     return self.class.where(id: id) unless parent_id
 
diff --git a/app/models/project.rb b/app/models/project.rb
index 57e91ab3b88..6e1cf9e31ee 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -17,6 +17,7 @@ class Project < ActiveRecord::Base
   include ProjectFeaturesCompatibility
   include SelectForProjectAuthorization
   include Routable
+  include GroupDescendant
 
   extend Gitlab::ConfigHelper
   extend Gitlab::CurrentSettings
@@ -81,6 +82,8 @@ class Project < ActiveRecord::Base
   belongs_to :creator, class_name: 'User'
   belongs_to :group, -> { where(type: 'Group') }, foreign_key: 'namespace_id'
   belongs_to :namespace
+  alias_method :parent, :namespace
+  alias_attribute :parent_id, :namespace_id
 
   has_one :last_event, -> {order 'events.created_at DESC'}, class_name: 'Event'
   has_many :boards, before_add: :validate_board_limit
@@ -479,6 +482,13 @@ class Project < ActiveRecord::Base
     end
   end
 
+  # returns all ancestor-groups upto but excluding the given namespace
+  # when no namespace is given, all ancestors upto the top are returned
+  def ancestors_upto(top = nil)
+    Gitlab::GroupHierarchy.new(Group.where(id: namespace_id))
+      .base_and_ancestors(upto: top)
+  end
+
   def lfs_enabled?
     return namespace.lfs_enabled? if self[:lfs_enabled].nil?
 
@@ -1549,10 +1559,6 @@ class Project < ActiveRecord::Base
     map.public_path_for_source_path(path)
   end
 
-  def parent
-    namespace
-  end
-
   def parent_changed?
     namespace_id_changed?
   end
diff --git a/app/serializers/base_serializer.rb b/app/serializers/base_serializer.rb
index 4e6c15f673b..8cade280b0c 100644
--- a/app/serializers/base_serializer.rb
+++ b/app/serializers/base_serializer.rb
@@ -1,6 +1,9 @@
 class BaseSerializer
-  def initialize(parameters = {})
-    @request = EntityRequest.new(parameters)
+  attr_reader :params
+
+  def initialize(params = {})
+    @params = params
+    @request = EntityRequest.new(params)
   end
 
   def represent(resource, opts = {}, entity_class = nil)
diff --git a/app/serializers/concerns/with_pagination.rb b/app/serializers/concerns/with_pagination.rb
new file mode 100644
index 00000000000..d29e22d6740
--- /dev/null
+++ b/app/serializers/concerns/with_pagination.rb
@@ -0,0 +1,22 @@
+module WithPagination
+  attr_accessor :paginator
+
+  def with_pagination(request, response)
+    tap { self.paginator = Gitlab::Serializer::Pagination.new(request, response) }
+  end
+
+  def paginated?
+    paginator.present?
+  end
+
+  # super is `BaseSerializer#represent` here.
+  #
+  # we shouldn't try to paginate single resources
+  def represent(resource, opts = {})
+    if paginated? && resource.respond_to?(:page)
+      super(@paginator.paginate(resource), opts)
+    else
+      super(resource, opts)
+    end
+  end
+end
diff --git a/app/serializers/environment_serializer.rb b/app/serializers/environment_serializer.rb
index 88842a9aa75..84722f33f59 100644
--- a/app/serializers/environment_serializer.rb
+++ b/app/serializers/environment_serializer.rb
@@ -1,4 +1,6 @@
 class EnvironmentSerializer < BaseSerializer
+  include WithPagination
+
   Item = Struct.new(:name, :size, :latest)
 
   entity EnvironmentEntity
@@ -7,18 +9,10 @@ class EnvironmentSerializer < BaseSerializer
     tap { @itemize = true }
   end
 
-  def with_pagination(request, response)
-    tap { @paginator = Gitlab::Serializer::Pagination.new(request, response) }
-  end
-
   def itemized?
     @itemize
   end
 
-  def paginated?
-    @paginator.present?
-  end
-
   def represent(resource, opts = {})
     if itemized?
       itemize(resource).map do |item|
@@ -27,8 +21,6 @@ class EnvironmentSerializer < BaseSerializer
           latest: super(item.latest, opts) }
       end
     else
-      resource = @paginator.paginate(resource) if paginated?
-
       super(resource, opts)
     end
   end
diff --git a/app/serializers/group_child_entity.rb b/app/serializers/group_child_entity.rb
new file mode 100644
index 00000000000..37240bfb0b1
--- /dev/null
+++ b/app/serializers/group_child_entity.rb
@@ -0,0 +1,77 @@
+class GroupChildEntity < Grape::Entity
+  include ActionView::Helpers::NumberHelper
+  include RequestAwareEntity
+
+  expose :id, :name, :description, :visibility, :full_name,
+         :created_at, :updated_at, :avatar_url
+
+  expose :type do |instance|
+    type
+  end
+
+  expose :can_edit do |instance|
+    return false unless request.respond_to?(:current_user)
+
+    can?(request.current_user, "admin_#{type}", instance)
+  end
+
+  expose :edit_path do |instance|
+    # We know `type` will be one either `project` or `group`.
+    # The `edit_polymorphic_path` helper would try to call the path helper
+    # with a plural: `edit_groups_path(instance)` or `edit_projects_path(instance)`
+    # while our methods are `edit_group_path` or `edit_group_path`
+    public_send("edit_#{type}_path", instance) # rubocop:disable GitlabSecurity/PublicSend
+  end
+
+  expose :relative_path do |instance|
+    polymorphic_path(instance)
+  end
+
+  expose :permission do |instance|
+    membership&.human_access
+  end
+
+  # Project only attributes
+  expose :star_count,
+         if: lambda { |_instance, _options| project? }
+
+  # Group only attributes
+  expose :children_count, :parent_id, :project_count, :subgroup_count,
+         unless: lambda { |_instance, _options| project? }
+
+  expose :leave_path, unless: lambda { |_instance, _options| project? } do |instance|
+    leave_group_members_path(instance)
+  end
+
+  expose :can_leave, unless: lambda { |_instance, _options| project? } do |instance|
+    if membership
+      can?(request.current_user, :destroy_group_member, membership)
+    else
+      false
+    end
+  end
+
+  expose :number_projects_with_delimiter, unless: lambda { |_instance, _options| project? } do |instance|
+    number_with_delimiter(instance.project_count)
+  end
+
+  expose :number_users_with_delimiter, unless: lambda { |_instance, _options| project? } do |instance|
+    number_with_delimiter(instance.member_count)
+  end
+
+  private
+
+  def membership
+    return unless request.current_user
+
+    @membership ||= request.current_user.members.find_by(source: object)
+  end
+
+  def project?
+    object.is_a?(Project)
+  end
+
+  def type
+    object.class.name.downcase
+  end
+end
diff --git a/app/serializers/group_child_serializer.rb b/app/serializers/group_child_serializer.rb
new file mode 100644
index 00000000000..2baef0a5703
--- /dev/null
+++ b/app/serializers/group_child_serializer.rb
@@ -0,0 +1,51 @@
+class GroupChildSerializer < BaseSerializer
+  include WithPagination
+
+  attr_reader :hierarchy_root, :should_expand_hierarchy
+
+  entity GroupChildEntity
+
+  def expand_hierarchy(hierarchy_root = nil)
+    @hierarchy_root = hierarchy_root
+    @should_expand_hierarchy = true
+
+    self
+  end
+
+  def represent(resource, opts = {}, entity_class = nil)
+    if should_expand_hierarchy
+      paginator.paginate(resource) if paginated?
+      represent_hierarchies(resource, opts)
+    else
+      super(resource, opts)
+    end
+  end
+
+  protected
+
+  def represent_hierarchies(children, opts)
+    if children.is_a?(GroupDescendant)
+      represent_hierarchy(children.hierarchy(hierarchy_root), opts).first
+    else
+      hierarchies = GroupDescendant.build_hierarchy(children, hierarchy_root)
+      # When an array was passed, we always want to represent an array.
+      # Even if the hierarchy only contains one element
+      represent_hierarchy(Array.wrap(hierarchies), opts)
+    end
+  end
+
+  def represent_hierarchy(hierarchy, opts)
+    serializer = self.class.new(params)
+
+    if hierarchy.is_a?(Hash)
+      hierarchy.map do |parent, children|
+        serializer.represent(parent, opts)
+          .merge(children: Array.wrap(serializer.represent_hierarchy(children, opts)))
+      end
+    elsif hierarchy.is_a?(Array)
+      hierarchy.flat_map { |child| serializer.represent_hierarchy(child, opts) }
+    else
+      serializer.represent(hierarchy, opts)
+    end
+  end
+end
diff --git a/app/serializers/group_serializer.rb b/app/serializers/group_serializer.rb
index 26e8566828b..8cf7eb63bcf 100644
--- a/app/serializers/group_serializer.rb
+++ b/app/serializers/group_serializer.rb
@@ -1,19 +1,5 @@
 class GroupSerializer < BaseSerializer
-  entity GroupEntity
-
-  def with_pagination(request, response)
-    tap { @paginator = Gitlab::Serializer::Pagination.new(request, response) }
-  end
+  include WithPagination
 
-  def paginated?
-    @paginator.present?
-  end
-
-  def represent(resource, opts = {})
-    if paginated?
-      super(@paginator.paginate(resource), opts)
-    else
-      super(resource, opts)
-    end
-  end
+  entity GroupEntity
 end
diff --git a/app/serializers/pipeline_serializer.rb b/app/serializers/pipeline_serializer.rb
index 661bf17983c..7181f8a6b04 100644
--- a/app/serializers/pipeline_serializer.rb
+++ b/app/serializers/pipeline_serializer.rb
@@ -1,16 +1,10 @@
 class PipelineSerializer < BaseSerializer
+  include WithPagination
+
   InvalidResourceError = Class.new(StandardError)
 
   entity PipelineDetailsEntity
 
-  def with_pagination(request, response)
-    tap { @paginator = Gitlab::Serializer::Pagination.new(request, response) }
-  end
-
-  def paginated?
-    @paginator.present?
-  end
-
   def represent(resource, opts = {})
     if resource.is_a?(ActiveRecord::Relation)
 
diff --git a/app/views/dashboard/_groups_head.html.haml b/app/views/dashboard/_groups_head.html.haml
index 7981daa0705..cebdbab4e74 100644
--- a/app/views/dashboard/_groups_head.html.haml
+++ b/app/views/dashboard/_groups_head.html.haml
@@ -1,13 +1,13 @@
 .top-area
   %ul.nav-links
     = nav_link(page: dashboard_groups_path) do
-      = link_to dashboard_groups_path, title: 'Your groups' do
+      = link_to dashboard_groups_path, title: _("Your groups") do
         Your groups
     = nav_link(page: explore_groups_path) do
-      = link_to explore_groups_path, title: 'Explore public groups' do
+      = link_to explore_groups_path, title: _("Explore public groups") do
         Explore public groups
   .nav-controls
     = render 'shared/groups/search_form'
     = render 'shared/groups/dropdown'
     - if current_user.can_create_group?
-      = link_to "New group", new_group_path, class: "btn btn-new"
+      = link_to _("New group"), new_group_path, class: "btn btn-new"
diff --git a/app/views/dashboard/groups/_empty_state.html.haml b/app/views/dashboard/groups/_empty_state.html.haml
deleted file mode 100644
index f5222fe631e..00000000000
--- a/app/views/dashboard/groups/_empty_state.html.haml
+++ /dev/null
@@ -1,7 +0,0 @@
-.groups-empty-state
-  = custom_icon("icon_empty_groups")
-
-  .text-content
-    %h4 A group is a collection of several projects.
-    %p If you organize your projects under a group, it works like a folder.
-    %p You can manage your group member’s permissions and access to each project in the group.
diff --git a/app/views/dashboard/groups/_groups.html.haml b/app/views/dashboard/groups/_groups.html.haml
index 168e6272d8e..601b6a8b1a7 100644
--- a/app/views/dashboard/groups/_groups.html.haml
+++ b/app/views/dashboard/groups/_groups.html.haml
@@ -1,9 +1,2 @@
 .js-groups-list-holder
-  #dashboard-group-app{ data: { endpoint: dashboard_groups_path(format: :json), path: dashboard_groups_path } }
-    .groups-list-loading
-      = icon('spinner spin', 'v-show' => 'isLoading')
-    %template{ 'v-if' => '!isLoading && isEmpty' }
-      %div{ 'v-cloak' => true }
-        = render 'empty_state'
-    %template{ 'v-else-if' => '!isLoading && !isEmpty' }
-      %groups-component{ ':groups' => 'state.groups', ':page-info' => 'state.pageInfo' }
+  #js-groups-tree{ data: { hide_projects: 'true', endpoint: dashboard_groups_path(format: :json), path: dashboard_groups_path, form_sel: 'form#group-filter-form', filter_sel: '.js-groups-list-filter', holder_sel: '.js-groups-list-holder', dropdown_sel: '.js-group-filter-dropdown-wrap' } }
diff --git a/app/views/dashboard/groups/index.html.haml b/app/views/dashboard/groups/index.html.haml
index 1cea8182733..25bf08c6c12 100644
--- a/app/views/dashboard/groups/index.html.haml
+++ b/app/views/dashboard/groups/index.html.haml
@@ -6,7 +6,7 @@
 = webpack_bundle_tag 'common_vue'
 = webpack_bundle_tag 'groups'
 
-- if @groups.empty?
-  = render 'empty_state'
+- if params[:filter].blank? && @groups.empty?
+  = render 'shared/groups/empty_state'
 - else
   = render 'groups'
diff --git a/app/views/explore/groups/_groups.html.haml b/app/views/explore/groups/_groups.html.haml
index 794c6d1d170..91149498248 100644
--- a/app/views/explore/groups/_groups.html.haml
+++ b/app/views/explore/groups/_groups.html.haml
@@ -1,6 +1,2 @@
 .js-groups-list-holder
-  %ul.content-list
-    - @groups.each do |group|
-      = render 'shared/groups/group', group: group
-
-  = paginate @groups, theme: 'gitlab'
+  #js-groups-tree{ data: { hide_projects: 'true', endpoint: explore_groups_path(format: :json), path: explore_groups_path, form_sel: 'form#group-filter-form', filter_sel: '.js-groups-list-filter', holder_sel: '.js-groups-list-holder', dropdown_sel: '.js-group-filter-dropdown-wrap' } }
diff --git a/app/views/explore/groups/index.html.haml b/app/views/explore/groups/index.html.haml
index 2651ef37e67..86abdf547cc 100644
--- a/app/views/explore/groups/index.html.haml
+++ b/app/views/explore/groups/index.html.haml
@@ -2,6 +2,9 @@
 - page_title    "Groups"
 - header_title  "Groups", dashboard_groups_path
 
+= webpack_bundle_tag 'common_vue'
+= webpack_bundle_tag 'groups'
+
 - if current_user
   = render 'dashboard/groups_head'
 - else
@@ -17,7 +20,7 @@
       %p Below you will find all the groups that are public.
       %p You can easily contribute to them by requesting to join these groups.
 
-- if @groups.present?
-  = render 'groups'
-- else
+- if params[:filter].blank? && @groups.empty?
   .nothing-here-block No public groups
+- else
+  = render 'groups'
diff --git a/app/views/groups/_children.html.haml b/app/views/groups/_children.html.haml
new file mode 100644
index 00000000000..3afb6b2f849
--- /dev/null
+++ b/app/views/groups/_children.html.haml
@@ -0,0 +1,5 @@
+= webpack_bundle_tag 'common_vue'
+= webpack_bundle_tag 'groups'
+
+.js-groups-list-holder
+  #js-groups-tree{ data: { hide_projects: 'false', group_id: group.id, endpoint: group_children_path(group, format: :json), path: group_path(group), form_sel: 'form#group-filter-form', filter_sel: '.js-groups-list-filter', holder_sel: '.js-groups-list-holder', dropdown_sel: '.js-group-filter-dropdown-wrap' } }
diff --git a/app/views/groups/_show_nav.html.haml b/app/views/groups/_show_nav.html.haml
deleted file mode 100644
index 35b75bc0923..00000000000
--- a/app/views/groups/_show_nav.html.haml
+++ /dev/null
@@ -1,8 +0,0 @@
-%ul.nav-links
-  = nav_link(page: group_path(@group)) do
-    = link_to group_path(@group) do
-      Projects
-  - if Group.supports_nested_groups?
-    = nav_link(page: subgroups_group_path(@group)) do
-      = link_to subgroups_group_path(@group) do
-        Subgroups
diff --git a/app/views/groups/show.html.haml b/app/views/groups/show.html.haml
index 3ca63f9c3e0..7f9486d08d9 100644
--- a/app/views/groups/show.html.haml
+++ b/app/views/groups/show.html.haml
@@ -1,5 +1,6 @@
 - @no_container = true
 - breadcrumb_title "Details"
+- can_create_subgroups = can?(current_user, :create_subgroup, @group)
 
 = content_for :meta_tags do
   = auto_discovery_link_tag(:atom, group_url(@group, rss_url_options), title: "#{@group.name} activity")
@@ -7,13 +8,38 @@
 = render 'groups/home_panel'
 
 .groups-header{ class: container_class }
-  .top-area
-    = render 'groups/show_nav'
-    .nav-controls
-      = render 'shared/projects/search_form'
-      = render 'shared/projects/dropdown'
+  .group-nav-container
+    .nav-controls.clearfix
+      = render "shared/groups/search_form"
+      = render "shared/groups/dropdown", show_archive_options: true
       - if can? current_user, :create_projects, @group
-        = link_to new_project_path(namespace_id: @group.id), class: 'btn btn-new pull-right' do
-          New Project
+        - new_project_label = _("New project")
+        - new_subgroup_label = _("New subgroup")
+        - if can_create_subgroups
+          .btn-group.new-project-subgroup.droplab-dropdown.js-new-project-subgroup{ data: { project_path: new_project_path(namespace_id: @group.id), subgroup_path: new_group_path(parent_id: @group.id) } }
+            %input.btn.btn-success.dropdown-primary.js-new-group-child{ type: "button", value: new_project_label, data: { action: "new-project" } }
+            %button.btn.btn-success.dropdown-toggle.js-dropdown-toggle{ type: "button", data: { "dropdown-trigger" => "#new-project-or-subgroup-dropdown" } }
+              = icon("caret-down", class: "dropdown-btn-icon")
+            %ul#new-project-or-subgroup-dropdown.dropdown-menu.dropdown-menu-align-right{ data: { dropdown: true } }
+              %li.droplab-item-selected{ role: "button", data: { value: "new-project", text: new_project_label } }
+                .menu-item
+                  .icon-container
+                    = icon("check", class: "list-item-checkmark")
+                  .description
+                    %strong= new_project_label
+                    %span= s_("GroupsTree|Create a project in this group.")
+              %li.divider.droplap-item-ignore
+              %li{ role: "button", data: { value: "new-subgroup", text: new_subgroup_label } }
+                .menu-item
+                  .icon-container
+                    = icon("check", class: "list-item-checkmark")
+                  .description
+                    %strong= new_subgroup_label
+                    %span= s_("GroupsTree|Create a subgroup in this group.")
+        - else
+          = link_to new_project_label, new_project_path(namespace_id: @group.id), class: "btn btn-success"
 
-  = render "projects", projects: @projects
+  - if params[:filter].blank? && !@has_children
+    = render "shared/groups/empty_state"
+  - else
+    = render "children", children: @children, group: @group
diff --git a/app/views/groups/subgroups.html.haml b/app/views/groups/subgroups.html.haml
deleted file mode 100644
index 869b3b243c6..00000000000
--- a/app/views/groups/subgroups.html.haml
+++ /dev/null
@@ -1,21 +0,0 @@
-- breadcrumb_title "Details"
-- @no_container = true
-
-= render 'groups/home_panel'
-
-.groups-header{ class: container_class }
-  .top-area
-    = render 'groups/show_nav'
-    .nav-controls
-      = form_tag request.path, method: :get do |f|
-        = search_field_tag :filter_groups, params[:filter_groups], placeholder: 'Filter by name', class: 'form-control', spellcheck: false
-      - if can?(current_user, :create_subgroup, @group)
-        = link_to new_group_path(parent_id: @group.id), class: 'btn btn-new pull-right' do
-          New Subgroup
-
-  - if @nested_groups.present?
-    %ul.content-list
-      = render partial: 'shared/groups/group', collection: @nested_groups, locals: { full_name: false }
-  - else
-    .nothing-here-block
-      There are no subgroups to show.
diff --git a/app/views/shared/groups/_dropdown.html.haml b/app/views/shared/groups/_dropdown.html.haml
index 760370a6984..8e6747ca740 100644
--- a/app/views/shared/groups/_dropdown.html.haml
+++ b/app/views/shared/groups/_dropdown.html.haml
@@ -1,18 +1,32 @@
-.dropdown.inline.js-group-filter-dropdown-wrap
+- show_archive_options = local_assigns.fetch(:show_archive_options, false)
+- if @sort.present?
+  - default_sort_by = @sort
+- else
+  - if params[:sort]
+    - default_sort_by = params[:sort]
+  - else
+    - default_sort_by = sort_value_recently_created
+
+.dropdown.inline.js-group-filter-dropdown-wrap.append-right-10
   %button.dropdown-toggle{ type: 'button', 'data-toggle' => 'dropdown' }
     %span.dropdown-label
-      - if @sort.present?
-        = sort_options_hash[@sort]
-      - else
-        = sort_title_recently_created
+      = sort_options_hash[default_sort_by]
     = icon('chevron-down')
-  %ul.dropdown-menu.dropdown-menu-align-right
-    %li
-      = link_to filter_groups_path(sort: sort_value_recently_created) do
-        = sort_title_recently_created
-      = link_to filter_groups_path(sort: sort_value_oldest_created) do
-        = sort_title_oldest_created
-      = link_to filter_groups_path(sort: sort_value_recently_updated) do
-        = sort_title_recently_updated
-      = link_to filter_groups_path(sort: sort_value_oldest_updated) do
-        = sort_title_oldest_updated
+  %ul.dropdown-menu.dropdown-menu-align-right.dropdown-menu-selectable
+    %li.dropdown-header
+      = _("Sort by")
+    - groups_sort_options_hash.each do |value, title|
+      %li.js-filter-sort-order
+        = link_to filter_groups_path(sort: value), class: ("is-active" if default_sort_by == value) do
+          = title
+    - if show_archive_options
+      %li.divider
+      %li.js-filter-archived-projects
+        = link_to group_children_path(@group, archived: nil), class: ("is-active" unless params[:archived].present?) do
+          Hide archived projects
+      %li.js-filter-archived-projects
+        = link_to group_children_path(@group, archived: true), class: ("is-active" if Gitlab::Utils.to_boolean(params[:archived])) do
+          Show archived projects
+      %li.js-filter-archived-projects
+        = link_to group_children_path(@group, archived: 'only'), class: ("is-active" if params[:archived] == 'only') do
+          Show archived projects only
diff --git a/app/views/shared/groups/_empty_state.html.haml b/app/views/shared/groups/_empty_state.html.haml
new file mode 100644
index 00000000000..13bb4baee3f
--- /dev/null
+++ b/app/views/shared/groups/_empty_state.html.haml
@@ -0,0 +1,7 @@
+.groups-empty-state
+  = custom_icon("icon_empty_groups")
+
+  .text-content
+    %h4= s_("GroupsEmptyState|A group is a collection of several projects.")
+    %p= s_("GroupsEmptyState|If you organize your projects under a group, it works like a folder.")
+    %p= s_("GroupsEmptyState|You can manage your group member’s permissions and access to each project in the group.")
diff --git a/app/views/shared/groups/_group.html.haml b/app/views/shared/groups/_group.html.haml
index 63f62eb476e..059dd24be6d 100644
--- a/app/views/shared/groups/_group.html.haml
+++ b/app/views/shared/groups/_group.html.haml
@@ -11,7 +11,7 @@
         = link_to edit_group_path(group), class: "btn" do
           = icon('cogs')
 
-      = link_to leave_group_group_members_path(group), data: { confirm: leave_confirmation_message(group) }, method: :delete, class: "btn", title: 'Leave this group' do
+      = link_to leave_group_group_members_path(group), data: { confirm: leave_confirmation_message(group) }, method: :delete, class: "btn", title: s_("GroupsTree|Leave this group") do
         = icon('sign-out')
 
   .stats
diff --git a/app/views/shared/groups/_list.html.haml b/app/views/shared/groups/_list.html.haml
index 427595c47a5..aec8ecd1714 100644
--- a/app/views/shared/groups/_list.html.haml
+++ b/app/views/shared/groups/_list.html.haml
@@ -3,4 +3,4 @@
     - groups.each_with_index do |group, i|
       = render "shared/groups/group", group: group
 - else
-  .nothing-here-block No groups found
+  .nothing-here-block= s_("GroupsEmptyState|No groups found")
diff --git a/app/views/shared/groups/_search_form.html.haml b/app/views/shared/groups/_search_form.html.haml
index ad7a7faedf1..3f91263089a 100644
--- a/app/views/shared/groups/_search_form.html.haml
+++ b/app/views/shared/groups/_search_form.html.haml
@@ -1,2 +1,2 @@
-= form_tag request.path, method: :get, class: 'group-filter-form', id: 'group-filter-form' do |f|
-  = search_field_tag :filter_groups, params[:filter_groups], placeholder: 'Filter by name...', class: 'group-filter-form-field form-control input-short js-groups-list-filter', spellcheck: false, id: 'group-filter-form-field', tabindex: "2"
+= form_tag request.path, method: :get, class: 'group-filter-form append-right-10', id: 'group-filter-form' do |f|
+  = search_field_tag :filter, params[:filter], placeholder: s_('GroupsTree|Filter by name...'), class: 'group-filter-form-field form-control input-short js-groups-list-filter', spellcheck: false, id: 'group-filter-form-field', tabindex: "2"
diff --git a/app/views/shared/projects/_dropdown.html.haml b/app/views/shared/projects/_dropdown.html.haml
index 80432a73e4e..3d917346f6b 100644
--- a/app/views/shared/projects/_dropdown.html.haml
+++ b/app/views/shared/projects/_dropdown.html.haml
@@ -1,5 +1,5 @@
 - @sort ||= sort_value_latest_activity
-.dropdown
+.dropdown.js-project-filter-dropdown-wrap
   - toggle_text = projects_sort_options_hash[@sort]
   = dropdown_toggle(toggle_text, { toggle: 'dropdown' }, { id: 'sort-projects-dropdown' })
   %ul.dropdown-menu.dropdown-menu-align-right.dropdown-menu-selectable
diff --git a/changelogs/unreleased/bvl-group-trees.yml b/changelogs/unreleased/bvl-group-trees.yml
new file mode 100644
index 00000000000..9f76eb81627
--- /dev/null
+++ b/changelogs/unreleased/bvl-group-trees.yml
@@ -0,0 +1,5 @@
+---
+title: Show collapsible project lists
+merge_request: 14055
+author:
+type: changed
diff --git a/config/application.rb b/config/application.rb
index 31e91835b9e..5100ec5d2b7 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -29,6 +29,7 @@ module Gitlab
                                      #{config.root}/app/models/project_services
                                      #{config.root}/app/workers/concerns
                                      #{config.root}/app/services/concerns
+                                     #{config.root}/app/serializers/concerns
                                      #{config.root}/app/finders/concerns])
 
     config.generators.templates.push("#{config.root}/generator_templates")
diff --git a/config/routes/group.rb b/config/routes/group.rb
index 8cc30bfcc50..702df5b7b5a 100644
--- a/config/routes/group.rb
+++ b/config/routes/group.rb
@@ -32,6 +32,8 @@ scope(path: 'groups/*group_id',
     end
 
     resources :variables, only: [:index, :show, :update, :create, :destroy]
+
+    resources :children, only: [:index]
   end
 end
 
@@ -43,7 +45,6 @@ scope(path: 'groups/*id',
   get :merge_requests, as: :merge_requests_group
   get :projects, as: :projects_group
   get :activity, as: :activity_group
-  get :subgroups, as: :subgroups_group
   get '/', action: :show, as: :group_canonical
 end
 
diff --git a/features/explore/groups.feature b/features/explore/groups.feature
index 9eacbe0b25e..830810615e0 100644
--- a/features/explore/groups.feature
+++ b/features/explore/groups.feature
@@ -3,6 +3,7 @@ Feature: Explore Groups
   Background:
     Given group "TestGroup" has private project "Enterprise"
 
+  @javascript
   Scenario: I should see group with private and internal projects as user
     Given group "TestGroup" has internal project "Internal"
     When I sign in as a user
@@ -10,6 +11,7 @@ Feature: Explore Groups
     Then I should see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group issues for internal project as user
     Given group "TestGroup" has internal project "Internal"
     When I sign in as a user
@@ -17,6 +19,7 @@ Feature: Explore Groups
     Then I should see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group merge requests for internal project as user
     Given group "TestGroup" has internal project "Internal"
     When I sign in as a user
@@ -24,6 +27,7 @@ Feature: Explore Groups
     Then I should see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group with private, internal and public projects as visitor
     Given group "TestGroup" has internal project "Internal"
     Given group "TestGroup" has public project "Community"
@@ -32,6 +36,7 @@ Feature: Explore Groups
     And I should not see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group issues for public project as visitor
     Given group "TestGroup" has internal project "Internal"
     Given group "TestGroup" has public project "Community"
@@ -40,6 +45,7 @@ Feature: Explore Groups
     And I should not see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group merge requests for public project as visitor
     Given group "TestGroup" has internal project "Internal"
     Given group "TestGroup" has public project "Community"
@@ -48,6 +54,7 @@ Feature: Explore Groups
     And I should not see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group with private, internal and public projects as user
     Given group "TestGroup" has internal project "Internal"
     Given group "TestGroup" has public project "Community"
@@ -57,6 +64,7 @@ Feature: Explore Groups
     And I should see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group issues for internal and public projects as user
     Given group "TestGroup" has internal project "Internal"
     Given group "TestGroup" has public project "Community"
@@ -66,6 +74,7 @@ Feature: Explore Groups
     And I should see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group merge requests for internal and public projects as user
     Given group "TestGroup" has internal project "Internal"
     Given group "TestGroup" has public project "Community"
@@ -75,17 +84,20 @@ Feature: Explore Groups
     And I should see project "Internal" items
     And I should not see project "Enterprise" items
 
+  @javascript
   Scenario: I should see group with public project in public groups area
     Given group "TestGroup" has public project "Community"
     When I visit the public groups area
     Then I should see group "TestGroup"
 
+  @javascript
   Scenario: I should see group with public project in public groups area as user
     Given group "TestGroup" has public project "Community"
     When I sign in as a user
     And I visit the public groups area
     Then I should see group "TestGroup"
 
+  @javascript
   Scenario: I should see group with internal project in public groups area as user
     Given group "TestGroup" has internal project "Internal"
     When I sign in as a user
diff --git a/lib/gitlab/group_hierarchy.rb b/lib/gitlab/group_hierarchy.rb
index 635f52131f9..42ded7c286f 100644
--- a/lib/gitlab/group_hierarchy.rb
+++ b/lib/gitlab/group_hierarchy.rb
@@ -17,12 +17,32 @@ module Gitlab
       @model = ancestors_base.model
     end
 
+    # Returns the set of descendants of a given relation, but excluding the given
+    # relation
+    def descendants
+      base_and_descendants.where.not(id: descendants_base.select(:id))
+    end
+
+    # Returns the set of ancestors of a given relation, but excluding the given
+    # relation
+    #
+    # Passing an `upto` will stop the recursion once the specified parent_id is
+    # reached. So all ancestors *lower* than the specified ancestor will be
+    # included.
+    def ancestors(upto: nil)
+      base_and_ancestors(upto: upto).where.not(id: ancestors_base.select(:id))
+    end
+
     # Returns a relation that includes the ancestors_base set of groups
     # and all their ancestors (recursively).
-    def base_and_ancestors
+    #
+    # Passing an `upto` will stop the recursion once the specified parent_id is
+    # reached. So all ancestors *lower* than the specified acestor will be
+    # included.
+    def base_and_ancestors(upto: nil)
       return ancestors_base unless Group.supports_nested_groups?
 
-      read_only(base_and_ancestors_cte.apply_to(model.all))
+      read_only(base_and_ancestors_cte(upto).apply_to(model.all))
     end
 
     # Returns a relation that includes the descendants_base set of groups
@@ -78,17 +98,19 @@ module Gitlab
 
     private
 
-    def base_and_ancestors_cte
+    def base_and_ancestors_cte(stop_id = nil)
       cte = SQL::RecursiveCTE.new(:base_and_ancestors)
 
       cte << ancestors_base.except(:order)
 
       # Recursively get all the ancestors of the base set.
-      cte << model
+      parent_query = model
         .from([groups_table, cte.table])
         .where(groups_table[:id].eq(cte.table[:parent_id]))
         .except(:order)
+      parent_query = parent_query.where(cte.table[:parent_id].not_eq(stop_id)) if stop_id
 
+      cte << parent_query
       cte
     end
 
diff --git a/lib/gitlab/multi_collection_paginator.rb b/lib/gitlab/multi_collection_paginator.rb
new file mode 100644
index 00000000000..eb3c9002710
--- /dev/null
+++ b/lib/gitlab/multi_collection_paginator.rb
@@ -0,0 +1,61 @@
+module Gitlab
+  class MultiCollectionPaginator
+    attr_reader :first_collection, :second_collection, :per_page
+
+    def initialize(*collections, per_page: nil)
+      raise ArgumentError.new('Only 2 collections are supported') if collections.size != 2
+
+      @per_page = per_page || Kaminari.config.default_per_page
+      @first_collection, @second_collection = collections
+    end
+
+    def paginate(page)
+      page = page.to_i
+      paginated_first_collection(page) + paginated_second_collection(page)
+    end
+
+    def total_count
+      @total_count ||= first_collection.size + second_collection.size
+    end
+
+    private
+
+    def paginated_first_collection(page)
+      @first_collection_pages ||= Hash.new do |hash, page|
+        hash[page] = first_collection.page(page).per(per_page)
+      end
+
+      @first_collection_pages[page]
+    end
+
+    def paginated_second_collection(page)
+      @second_collection_pages ||= Hash.new do |hash, page|
+        second_collection_page = page - first_collection_page_count
+
+        offset = if second_collection_page < 1 || first_collection_page_count.zero?
+                   0
+                 else
+                   per_page - first_collection_last_page_size
+                 end
+        hash[page] = second_collection.page(second_collection_page)
+                       .per(per_page - paginated_first_collection(page).size)
+                       .padding(offset)
+      end
+
+      @second_collection_pages[page]
+    end
+
+    def first_collection_page_count
+      return @first_collection_page_count if defined?(@first_collection_page_count)
+
+      first_collection_page = paginated_first_collection(0)
+      @first_collection_page_count = first_collection_page.total_pages
+    end
+
+    def first_collection_last_page_size
+      return @first_collection_last_page_size if defined?(@first_collection_last_page_size)
+
+      @first_collection_last_page_size = paginated_first_collection(first_collection_page_count).count
+    end
+  end
+end
diff --git a/lib/gitlab/path_regex.rb b/lib/gitlab/path_regex.rb
index 894bd5efae5..22f8dd669d0 100644
--- a/lib/gitlab/path_regex.rb
+++ b/lib/gitlab/path_regex.rb
@@ -128,7 +128,6 @@ module Gitlab
       notification_setting
       pipeline_quota
       projects
-      subgroups
     ].freeze
 
     ILLEGAL_PROJECT_PATH_WORDS = PROJECT_WILDCARD_ROUTES
diff --git a/lib/gitlab/sql/union.rb b/lib/gitlab/sql/union.rb
index f30c771837a..c99b262f1ca 100644
--- a/lib/gitlab/sql/union.rb
+++ b/lib/gitlab/sql/union.rb
@@ -26,7 +26,11 @@ module Gitlab
           @relations.map { |rel| rel.reorder(nil).to_sql }.reject(&:blank?)
         end
 
-        fragments.join("\n#{union_keyword}\n")
+        if fragments.any?
+          fragments.join("\n#{union_keyword}\n")
+        else
+          'NULL'
+        end
       end
 
       def union_keyword
diff --git a/lib/gitlab/utils/merge_hash.rb b/lib/gitlab/utils/merge_hash.rb
new file mode 100644
index 00000000000..385141d44d0
--- /dev/null
+++ b/lib/gitlab/utils/merge_hash.rb
@@ -0,0 +1,117 @@
+module Gitlab
+  module Utils
+    module MergeHash
+      extend self
+      # Deep merges an array of hashes
+      #
+      # [{ hello: ["world"] },
+      #  { hello: "Everyone" },
+      #  { hello: { greetings: ['Bonjour', 'Hello', 'Hallo', 'Dzien dobry'] } },
+      #   "Goodbye", "Hallo"]
+      # =>  [
+      #       {
+      #         hello:
+      #           [
+      #             "world",
+      #             "Everyone",
+      #             { greetings: ['Bonjour', 'Hello', 'Hallo', 'Dzien dobry'] }
+      #           ]
+      #       },
+      #       "Goodbye"
+      #     ]
+      def merge(elements)
+        merged, *other_elements = elements
+
+        other_elements.each do |element|
+          merged = merge_hash_tree(merged, element)
+        end
+
+        merged
+      end
+
+      # This extracts all keys and values from a hash into an array
+      #
+      # { hello: "world", this: { crushes: ["an entire", "hash"] } }
+      # => [:hello, "world", :this, :crushes, "an entire", "hash"]
+      def crush(array_or_hash)
+        if array_or_hash.is_a?(Array)
+          crush_array(array_or_hash)
+        else
+          crush_hash(array_or_hash)
+        end
+      end
+
+      private
+
+      def merge_hash_into_array(array, new_hash)
+        crushed_new_hash = crush_hash(new_hash)
+        # Merge the hash into an existing element of the array if there is overlap
+        if mergeable_index = array.index { |element| crushable?(element) && (crush(element) & crushed_new_hash).any? }
+          array[mergeable_index] = merge_hash_tree(array[mergeable_index], new_hash)
+        else
+          array << new_hash
+        end
+
+        array
+      end
+
+      def merge_hash_tree(first_element, second_element)
+        # If one of the elements is an object, and the other is a Hash or Array
+        # we can check if the object is already included. If so, we don't need to do anything
+        #
+        # Handled cases
+        # [Hash, Object], [Array, Object]
+        if crushable?(first_element) && crush(first_element).include?(second_element)
+          first_element
+        elsif crushable?(second_element) && crush(second_element).include?(first_element)
+          second_element
+        # When the first is an array, we need to go over every element to see if
+        # we can merge deeper. If no match is found, we add the element to the array
+        #
+        # Handled cases:
+        # [Array, Hash]
+        elsif first_element.is_a?(Array) && second_element.is_a?(Hash)
+          merge_hash_into_array(first_element, second_element)
+        elsif first_element.is_a?(Hash) && second_element.is_a?(Array)
+          merge_hash_into_array(second_element, first_element)
+        # If both of them are hashes, we can deep_merge with the same logic
+        #
+        # Handled cases:
+        # [Hash, Hash]
+        elsif first_element.is_a?(Hash) && second_element.is_a?(Hash)
+          first_element.deep_merge(second_element) { |key, first, second| merge_hash_tree(first, second) }
+        # If both elements are arrays, we try to merge each element separatly
+        #
+        # Handled cases
+        # [Array, Array]
+        elsif first_element.is_a?(Array) && second_element.is_a?(Array)
+          first_element.map { |child_element| merge_hash_tree(child_element, second_element) }
+        # If one or both elements are a GroupDescendant, we wrap create an array
+        # combining them.
+        #
+        # Handled cases:
+        # [Object, Object], [Array, Array]
+        else
+          (Array.wrap(first_element) + Array.wrap(second_element)).uniq
+        end
+      end
+
+      def crushable?(element)
+        element.is_a?(Hash) || element.is_a?(Array)
+      end
+
+      def crush_hash(hash)
+        hash.flat_map do |key, value|
+          crushed_value = crushable?(value) ? crush(value) : value
+          Array.wrap(key) + Array.wrap(crushed_value)
+        end
+      end
+
+      def crush_array(array)
+        array.flat_map do |element|
+          crushable?(element) ? crush(element) : element
+        end
+      end
+    end
+  end
+end
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index c73e582e608..1f356a231b0 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -8,8 +8,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: gitlab 1.0.0\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2017-10-06 18:33+0200\n"
-"PO-Revision-Date: 2017-10-06 18:33+0200\n"
+"POT-Creation-Date: 2017-10-10 17:50+0200\n"
+"PO-Revision-Date: 2017-10-10 17:50+0200\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
 "Language: \n"
@@ -109,6 +109,9 @@ msgstr ""
 msgid "All"
 msgstr ""
 
+msgid "An error occurred. Please try again."
+msgstr ""
+
 msgid "Appearance"
 msgstr ""
 
@@ -375,6 +378,9 @@ msgstr ""
 msgid "Clone repository"
 msgstr ""
 
+msgid "Cluster"
+msgstr ""
+
 msgid "ClusterIntegration|A %{link_to_container_project} must have been created under this account"
 msgstr ""
 
@@ -420,13 +426,10 @@ msgstr ""
 msgid "ClusterIntegration|Google Container Engine project"
 msgstr ""
 
-msgid "ClusterIntegration|Google Container Engine"
-msgstr ""
-
 msgid "ClusterIntegration|Learn more about %{link_to_documentation}"
 msgstr ""
 
-msgid "ClusterIntegration|See machine types"
+msgid "ClusterIntegration|Machine type"
 msgstr ""
 
 msgid "ClusterIntegration|Make sure your account %{link_to_requirements} to create clusters"
@@ -438,9 +441,15 @@ msgstr ""
 msgid "ClusterIntegration|Number of nodes"
 msgstr ""
 
+msgid "ClusterIntegration|Please make sure that your Google account meets the following requirements:"
+msgstr ""
+
 msgid "ClusterIntegration|Project namespace (optional, unique)"
 msgstr ""
 
+msgid "ClusterIntegration|Read our %{link_to_help_page} on cluster integration."
+msgstr ""
+
 msgid "ClusterIntegration|Remove cluster integration"
 msgstr ""
 
@@ -450,7 +459,10 @@ msgstr ""
 msgid "ClusterIntegration|Removing cluster integration will remove the cluster configuration you have added to this project. It will not delete your project."
 msgstr ""
 
-msgid "ClusterIntegration|Save changes"
+msgid "ClusterIntegration|Save"
+msgstr ""
+
+msgid "ClusterIntegration|See machine types"
 msgstr ""
 
 msgid "ClusterIntegration|See your projects"
@@ -462,18 +474,12 @@ msgstr ""
 msgid "ClusterIntegration|Something went wrong on our end."
 msgstr ""
 
-msgid "ClusterIntegration|Something went wrong while creating your cluster on Google Container Engine."
-msgstr ""
-
-msgid "ClusterIntegration|Please make sure that your Google account meets the following requirements:"
+msgid "ClusterIntegration|Something went wrong while creating your cluster on Google Container Engine"
 msgstr ""
 
 msgid "ClusterIntegration|Toggle Cluster"
 msgstr ""
 
-msgid "ClusterIntegration|Read our %{link_to_help_page} on cluster integration."
-msgstr ""
-
 msgid "ClusterIntegration|With a cluster associated to this project, you can use review apps, deploy your applications, run your pipelines, and much more in an easy way."
 msgstr ""
 
@@ -691,6 +697,9 @@ msgstr ""
 msgid "Discard changes"
 msgstr ""
 
+msgid "Dismiss Cycle Analytics introduction box"
+msgstr ""
+
 msgid "Don't show again"
 msgstr ""
 
@@ -760,6 +769,9 @@ msgstr ""
 msgid "Explore projects"
 msgstr ""
 
+msgid "Explore public groups"
+msgstr ""
+
 msgid "Failed to change the owner"
 msgstr ""
 
@@ -846,6 +858,51 @@ msgstr ""
 msgid "GroupSettings|remove the share with group lock from %{ancestor_group_name}"
 msgstr ""
 
+msgid "GroupsEmptyState|A group is a collection of several projects."
+msgstr ""
+
+msgid "GroupsEmptyState|If you organize your projects under a group, it works like a folder."
+msgstr ""
+
+msgid "GroupsEmptyState|No groups found"
+msgstr ""
+
+msgid "GroupsEmptyState|You can manage your group member’s permissions and access to each project in the group."
+msgstr ""
+
+msgid "GroupsTreeRole|as"
+msgstr ""
+
+msgid "GroupsTree|Are you sure you want to leave the \"${this.group.fullName}\" group?"
+msgstr ""
+
+msgid "GroupsTree|Create a project in this group."
+msgstr ""
+
+msgid "GroupsTree|Create a subgroup in this group."
+msgstr ""
+
+msgid "GroupsTree|Edit group"
+msgstr ""
+
+msgid "GroupsTree|Failed to leave the group. Please make sure you are not the only owner."
+msgstr ""
+
+msgid "GroupsTree|Filter by name..."
+msgstr ""
+
+msgid "GroupsTree|Leave this group"
+msgstr ""
+
+msgid "GroupsTree|Loading groups"
+msgstr ""
+
+msgid "GroupsTree|Sorry, no groups matched your search"
+msgstr ""
+
+msgid "GroupsTree|Sorry, no groups or projects matched your search"
+msgstr ""
+
 msgid "Health Check"
 msgstr ""
 
@@ -876,6 +933,12 @@ msgstr ""
 msgid "Install a Runner compatible with GitLab CI"
 msgstr ""
 
+msgid "Internal - The group and any internal projects can be viewed by any logged in user."
+msgstr ""
+
+msgid "Internal - The project can be accessed by any logged in user."
+msgstr ""
+
 msgid "Interval Pattern"
 msgstr ""
 
@@ -935,6 +998,9 @@ msgstr ""
 msgid "Learn more in the|pipeline schedules documentation"
 msgstr ""
 
+msgid "Leave"
+msgstr ""
+
 msgid "Leave group"
 msgstr ""
 
@@ -946,6 +1012,15 @@ msgid_plural "Limited to showing %d events at most"
 msgstr[0] ""
 msgstr[1] ""
 
+msgid "Lock"
+msgstr ""
+
+msgid "Locked"
+msgstr ""
+
+msgid "Login"
+msgstr ""
+
 msgid "Median"
 msgstr ""
 
@@ -973,6 +1048,9 @@ msgstr ""
 msgid "More information is available|here"
 msgstr ""
 
+msgid "New Cluster"
+msgstr ""
+
 msgid "New Issue"
 msgid_plural "New Issues"
 msgstr[0] ""
@@ -990,18 +1068,27 @@ msgstr ""
 msgid "New file"
 msgstr ""
 
+msgid "New group"
+msgstr ""
+
 msgid "New issue"
 msgstr ""
 
 msgid "New merge request"
 msgstr ""
 
+msgid "New project"
+msgstr ""
+
 msgid "New schedule"
 msgstr ""
 
 msgid "New snippet"
 msgstr ""
 
+msgid "New subgroup"
+msgstr ""
+
 msgid "New tag"
 msgstr ""
 
@@ -1080,6 +1167,9 @@ msgstr ""
 msgid "OfSearchInADropdown|Filter"
 msgstr ""
 
+msgid "Only project members can comment."
+msgstr ""
+
 msgid "OpenedNDaysAgo|Opened"
 msgstr ""
 
@@ -1110,6 +1200,9 @@ msgstr ""
 msgid "Password"
 msgstr ""
 
+msgid "People without permission will never get a notification and won\\'t be able to comment."
+msgstr ""
+
 msgid "Pipeline"
 msgstr ""
 
@@ -1209,9 +1302,51 @@ msgstr ""
 msgid "Preferences"
 msgstr ""
 
+msgid "Private - Project access must be granted explicitly to each user."
+msgstr ""
+
+msgid "Private - The group and its projects can only be viewed by members."
+msgstr ""
+
 msgid "Profile"
 msgstr ""
 
+msgid "Profiles|Account scheduled for removal."
+msgstr ""
+
+msgid "Profiles|Delete Account"
+msgstr ""
+
+msgid "Profiles|Delete account"
+msgstr ""
+
+msgid "Profiles|Delete your account?"
+msgstr ""
+
+msgid "Profiles|Deleting an account has the following effects:"
+msgstr ""
+
+msgid "Profiles|Invalid password"
+msgstr ""
+
+msgid "Profiles|Invalid username"
+msgstr ""
+
+msgid "Profiles|Type your %{confirmationValue} to confirm:"
+msgstr ""
+
+msgid "Profiles|You don't have access to delete this user."
+msgstr ""
+
+msgid "Profiles|You must transfer ownership or delete these groups before you can delete your account."
+msgstr ""
+
+msgid "Profiles|Your account is currently an owner in these groups:"
+msgstr ""
+
+msgid "Profiles|your account"
+msgstr ""
+
 msgid "Project '%{project_name}' queued for deletion."
 msgstr ""
 
@@ -1266,6 +1401,9 @@ msgstr ""
 msgid "ProjectNetworkGraph|Graph"
 msgstr ""
 
+msgid "Projects"
+msgstr ""
+
 msgid "ProjectsDropdown|Frequently visited"
 msgstr ""
 
@@ -1287,6 +1425,12 @@ msgstr ""
 msgid "ProjectsDropdown|This feature requires browser localStorage support"
 msgstr ""
 
+msgid "Public - The group and any public projects can be viewed without any authentication."
+msgstr ""
+
+msgid "Public - The project can be accessed without any authentication."
+msgstr ""
+
 msgid "Push events"
 msgstr ""
 
@@ -1415,12 +1559,18 @@ msgstr ""
 msgid "Something went wrong on our end."
 msgstr ""
 
+msgid "Something went wrong trying to change the locked state of this ${this.issuableDisplayName(this.issuableType)}"
+msgstr ""
+
 msgid "Something went wrong while fetching the projects."
 msgstr ""
 
 msgid "Something went wrong while fetching the registry list."
 msgstr ""
 
+msgid "Sort by"
+msgstr ""
+
 msgid "SortOptions|Access level, ascending"
 msgstr ""
 
@@ -1529,6 +1679,9 @@ msgstr ""
 msgid "Start the Runner!"
 msgstr ""
 
+msgid "Subgroups"
+msgstr ""
+
 msgid "Switch branch/tag"
 msgstr ""
 
@@ -1600,12 +1753,24 @@ msgstr ""
 msgid "There are problems accessing Git storage: "
 msgstr ""
 
+msgid "This is a confidential issue."
+msgstr ""
+
 msgid "This is the author's first Merge Request to this project."
 msgstr ""
 
+msgid "This issue is confidential and locked."
+msgstr ""
+
+msgid "This issue is locked."
+msgstr ""
+
 msgid "This means you can not push code until you create an empty repository or import existing one."
 msgstr ""
 
+msgid "This merge request is locked."
+msgstr ""
+
 msgid "Time before an issue gets scheduled"
 msgstr ""
 
@@ -1760,6 +1925,12 @@ msgstr ""
 msgid "Total test time for all commits/merges"
 msgstr ""
 
+msgid "Unlock"
+msgstr ""
+
+msgid "Unlocked"
+msgstr ""
+
 msgid "Unstar"
 msgstr ""
 
@@ -1922,9 +2093,15 @@ msgstr ""
 msgid "You are going to transfer %{project_name_with_namespace} to another owner. Are you ABSOLUTELY sure?"
 msgstr ""
 
+msgid "You are on a read-only GitLab instance."
+msgstr ""
+
 msgid "You can only add files when you are on a branch"
 msgstr ""
 
+msgid "You cannot write to this read-only GitLab instance."
+msgstr ""
+
 msgid "You have reached your project limit"
 msgstr ""
 
@@ -1955,6 +2132,12 @@ msgstr ""
 msgid "You won't be able to pull or push project code via SSH until you %{add_ssh_key_link} to your profile"
 msgstr ""
 
+msgid "Your comment will not be visible to the public."
+msgstr ""
+
+msgid "Your groups"
+msgstr ""
+
 msgid "Your name"
 msgstr ""
 
@@ -1977,5 +2160,11 @@ msgid_plural "parents"
 msgstr[0] ""
 msgstr[1] ""
 
+msgid "password"
+msgstr ""
+
 msgid "personal access token"
 msgstr ""
+
+msgid "username"
+msgstr ""
diff --git a/spec/controllers/concerns/group_tree_spec.rb b/spec/controllers/concerns/group_tree_spec.rb
new file mode 100644
index 00000000000..ba84fbf8564
--- /dev/null
+++ b/spec/controllers/concerns/group_tree_spec.rb
@@ -0,0 +1,89 @@
+require 'spec_helper'
+
+describe GroupTree do
+  let(:group) { create(:group, :public) }
+  let(:user) { create(:user) }
+
+  controller(ApplicationController) do
+    # `described_class` is not available in this context
+    include GroupTree # rubocop:disable RSpec/DescribedClass
+
+    def index
+      render_group_tree GroupsFinder.new(current_user).execute
+    end
+  end
+
+  before do
+    group.add_owner(user)
+    sign_in(user)
+  end
+
+  describe 'GET #index' do
+    it 'filters groups' do
+      other_group = create(:group, name: 'filter')
+      other_group.add_owner(user)
+
+      get :index, filter: 'filt', format: :json
+
+      expect(assigns(:groups)).to contain_exactly(other_group)
+    end
+
+    context 'for subgroups', :nested_groups do
+      it 'only renders root groups when no parent was given' do
+        create(:group, :public, parent: group)
+
+        get :index, format: :json
+
+        expect(assigns(:groups)).to contain_exactly(group)
+      end
+
+      it 'contains only the subgroup when a parent was given' do
+        subgroup = create(:group, :public, parent: group)
+
+        get :index, parent_id: group.id, format: :json
+
+        expect(assigns(:groups)).to contain_exactly(subgroup)
+      end
+
+      it 'allows filtering for subgroups and includes the parents for rendering' do
+        subgroup = create(:group, :public, parent: group, name: 'filter')
+
+        get :index, filter: 'filt', format: :json
+
+        expect(assigns(:groups)).to contain_exactly(group, subgroup)
+      end
+
+      it 'does not include groups the user does not have access to' do
+        parent = create(:group, :private)
+        subgroup = create(:group, :private, parent: parent, name: 'filter')
+        subgroup.add_developer(user)
+        _other_subgroup = create(:group, :private, parent: parent, name: 'filte')
+
+        get :index, filter: 'filt', format: :json
+
+        expect(assigns(:groups)).to contain_exactly(parent, subgroup)
+      end
+    end
+
+    context 'json content' do
+      it 'shows groups as json' do
+        get :index, format: :json
+
+        expect(json_response.first['id']).to eq(group.id)
+      end
+
+      context 'nested groups', :nested_groups do
+        it 'expands the tree when filtering' do
+          subgroup = create(:group, :public, parent: group, name: 'filter')
+
+          get :index, filter: 'filt', format: :json
+
+          children_response = json_response.first['children']
+
+          expect(json_response.first['id']).to eq(group.id)
+          expect(children_response.first['id']).to eq(subgroup.id)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/controllers/dashboard/groups_controller_spec.rb b/spec/controllers/dashboard/groups_controller_spec.rb
new file mode 100644
index 00000000000..fb9d3efbac0
--- /dev/null
+++ b/spec/controllers/dashboard/groups_controller_spec.rb
@@ -0,0 +1,23 @@
+require 'spec_helper'
+
+describe Dashboard::GroupsController do
+  let(:user) { create(:user) }
+
+  before do
+    sign_in(user)
+  end
+
+  it 'renders group trees' do
+    expect(described_class).to include(GroupTree)
+  end
+
+  it 'only includes projects the user is a member of' do
+    member_of_group = create(:group)
+    member_of_group.add_developer(user)
+    create(:group, :public)
+
+    get :index
+
+    expect(assigns(:groups)).to contain_exactly(member_of_group)
+  end
+end
diff --git a/spec/controllers/explore/groups_controller_spec.rb b/spec/controllers/explore/groups_controller_spec.rb
new file mode 100644
index 00000000000..9e0ad9ea86f
--- /dev/null
+++ b/spec/controllers/explore/groups_controller_spec.rb
@@ -0,0 +1,23 @@
+require 'spec_helper'
+
+describe Explore::GroupsController do
+  let(:user) { create(:user) }
+
+  before do
+    sign_in(user)
+  end
+
+  it 'renders group trees' do
+    expect(described_class).to include(GroupTree)
+  end
+
+  it 'includes public projects' do
+    member_of_group = create(:group)
+    member_of_group.add_developer(user)
+    public_group = create(:group, :public)
+
+    get :index
+
+    expect(assigns(:groups)).to contain_exactly(member_of_group, public_group)
+  end
+end
diff --git a/spec/controllers/groups/children_controller_spec.rb b/spec/controllers/groups/children_controller_spec.rb
new file mode 100644
index 00000000000..4262d474e59
--- /dev/null
+++ b/spec/controllers/groups/children_controller_spec.rb
@@ -0,0 +1,286 @@
+require 'spec_helper'
+
+describe Groups::ChildrenController do
+  let(:group) { create(:group, :public) }
+  let(:user) { create(:user) }
+  let!(:group_member) { create(:group_member, group: group, user: user) }
+
+  describe 'GET #index' do
+    context 'for projects' do
+      let!(:public_project) { create(:project, :public, namespace: group) }
+      let!(:private_project) { create(:project, :private, namespace: group) }
+
+      context 'as a user' do
+        before do
+          sign_in(user)
+        end
+
+        it 'shows all children' do
+          get :index, group_id: group.to_param, format: :json
+
+          expect(assigns(:children)).to contain_exactly(public_project, private_project)
+        end
+
+        context 'being member of private subgroup' do
+          it 'shows public and private children the user is member of' do
+            group_member.destroy!
+            private_project.add_guest(user)
+
+            get :index, group_id: group.to_param, format: :json
+
+            expect(assigns(:children)).to contain_exactly(public_project, private_project)
+          end
+        end
+      end
+
+      context 'as a guest' do
+        it 'shows the public children' do
+          get :index, group_id: group.to_param, format: :json
+
+          expect(assigns(:children)).to contain_exactly(public_project)
+        end
+      end
+    end
+
+    context 'for subgroups', :nested_groups do
+      let!(:public_subgroup) { create(:group, :public, parent: group) }
+      let!(:private_subgroup) { create(:group, :private, parent: group) }
+      let!(:public_project) { create(:project, :public, namespace: group) }
+      let!(:private_project) { create(:project, :private, namespace: group) }
+
+      context 'as a user' do
+        before do
+          sign_in(user)
+        end
+
+        it 'shows all children' do
+          get :index, group_id: group.to_param, format: :json
+
+          expect(assigns(:children)).to contain_exactly(public_subgroup, private_subgroup, public_project, private_project)
+        end
+
+        context 'being member of private subgroup' do
+          it 'shows public and private children the user is member of' do
+            group_member.destroy!
+            private_subgroup.add_guest(user)
+            private_project.add_guest(user)
+
+            get :index, group_id: group.to_param, format: :json
+
+            expect(assigns(:children)).to contain_exactly(public_subgroup, private_subgroup, public_project, private_project)
+          end
+        end
+      end
+
+      context 'as a guest' do
+        it 'shows the public children' do
+          get :index, group_id: group.to_param, format: :json
+
+          expect(assigns(:children)).to contain_exactly(public_subgroup, public_project)
+        end
+      end
+
+      context 'filtering children' do
+        it 'expands the tree for matching projects' do
+          project = create(:project, :public, namespace: public_subgroup, name: 'filterme')
+
+          get :index, group_id: group.to_param, filter: 'filter', format: :json
+
+          group_json = json_response.first
+          project_json = group_json['children'].first
+
+          expect(group_json['id']).to eq(public_subgroup.id)
+          expect(project_json['id']).to eq(project.id)
+        end
+
+        it 'expands the tree for matching subgroups' do
+          matched_group = create(:group, :public, parent: public_subgroup, name: 'filterme')
+
+          get :index, group_id: group.to_param, filter: 'filter', format: :json
+
+          group_json = json_response.first
+          matched_group_json = group_json['children'].first
+
+          expect(group_json['id']).to eq(public_subgroup.id)
+          expect(matched_group_json['id']).to eq(matched_group.id)
+        end
+
+        it 'merges the trees correctly' do
+          shared_subgroup = create(:group, :public, parent: group, path: 'hardware')
+          matched_project_1 = create(:project, :public, namespace: shared_subgroup, name: 'mobile-soc')
+
+          l2_subgroup = create(:group, :public, parent: shared_subgroup, path: 'broadcom')
+          l3_subgroup = create(:group, :public,  parent: l2_subgroup, path: 'wifi-group')
+          matched_project_2 = create(:project, :public, namespace: l3_subgroup, name: 'mobile')
+
+          get :index, group_id: group.to_param, filter: 'mobile', format: :json
+
+          shared_group_json = json_response.first
+          expect(shared_group_json['id']).to eq(shared_subgroup.id)
+
+          matched_project_1_json = shared_group_json['children'].detect { |child| child['type'] == 'project' }
+          expect(matched_project_1_json['id']).to eq(matched_project_1.id)
+
+          l2_subgroup_json = shared_group_json['children'].detect { |child| child['type'] == 'group' }
+          expect(l2_subgroup_json['id']).to eq(l2_subgroup.id)
+
+          l3_subgroup_json = l2_subgroup_json['children'].first
+          expect(l3_subgroup_json['id']).to eq(l3_subgroup.id)
+
+          matched_project_2_json = l3_subgroup_json['children'].first
+          expect(matched_project_2_json['id']).to eq(matched_project_2.id)
+        end
+
+        it 'expands the tree upto a specified parent' do
+          subgroup = create(:group, :public, parent: group)
+          l2_subgroup = create(:group, :public, parent: subgroup)
+          create(:project, :public, namespace: l2_subgroup, name: 'test')
+
+          get :index, group_id: subgroup.to_param, filter: 'test', format: :json
+
+          expect(response).to have_http_status(200)
+        end
+
+        it 'returns an array with one element when only one result is matched' do
+          create(:project, :public, namespace: group, name: 'match')
+
+          get :index, group_id: group.to_param, filter: 'match', format: :json
+
+          expect(json_response).to be_kind_of(Array)
+          expect(json_response.size).to eq(1)
+        end
+
+        it 'returns an empty array when there are no search results' do
+          subgroup = create(:group, :public, parent: group)
+          l2_subgroup = create(:group, :public, parent: subgroup)
+          create(:project, :public, namespace: l2_subgroup, name: 'no-match')
+
+          get :index, group_id: subgroup.to_param, filter: 'test', format: :json
+
+          expect(json_response).to eq([])
+        end
+
+        it 'includes pagination headers' do
+          2.times { |i| create(:group, :public, parent: public_subgroup, name: "filterme#{i}") }
+
+          get :index, group_id: group.to_param, filter: 'filter', per_page: 1, format: :json
+
+          expect(response).to include_pagination_headers
+        end
+      end
+
+      context 'queries per rendered element', :request_store do
+        # We need to make sure the following counts are preloaded
+        # otherwise they will cause an extra query
+        # 1. Count of visible projects in the element
+        # 2. Count of visible subgroups in the element
+        # 3. Count of members of a group
+        let(:expected_queries_per_group) { 0 }
+        let(:expected_queries_per_project) { 0 }
+
+        def get_list
+          get :index, group_id: group.to_param, format: :json
+        end
+
+        it 'queries the expected amount for a group row' do
+          control = ActiveRecord::QueryRecorder.new { get_list }
+
+          _new_group = create(:group, :public, parent: group)
+
+          expect { get_list }.not_to exceed_query_limit(control).with_threshold(expected_queries_per_group)
+        end
+
+        it 'queries the expected amount for a project row' do
+          control = ActiveRecord::QueryRecorder.new { get_list }
+          _new_project = create(:project, :public, namespace: group)
+
+          expect { get_list }.not_to exceed_query_limit(control).with_threshold(expected_queries_per_project)
+        end
+
+        context 'when rendering hierarchies' do
+          # When loading hierarchies we load the all the ancestors for matched projects
+          # in 1 separate query
+          let(:extra_queries_for_hierarchies) { 1 }
+
+          def get_filtered_list
+            get :index, group_id: group.to_param, filter: 'filter', format: :json
+          end
+
+          it 'queries the expected amount when nested rows are increased for a group' do
+            matched_group = create(:group, :public, parent: group, name: 'filterme')
+
+            control = ActiveRecord::QueryRecorder.new { get_filtered_list }
+
+            matched_group.update!(parent: public_subgroup)
+
+            expect { get_filtered_list }.not_to exceed_query_limit(control).with_threshold(extra_queries_for_hierarchies)
+          end
+
+          it 'queries the expected amount when a new group match is added' do
+            create(:group, :public, parent: public_subgroup, name: 'filterme')
+
+            control = ActiveRecord::QueryRecorder.new { get_filtered_list }
+
+            create(:group, :public, parent: public_subgroup, name: 'filterme2')
+            create(:group, :public, parent: public_subgroup, name: 'filterme3')
+
+            expect { get_filtered_list }.not_to exceed_query_limit(control).with_threshold(extra_queries_for_hierarchies)
+          end
+
+          it 'queries the expected amount when nested rows are increased for a project' do
+            matched_project = create(:project, :public, namespace: group, name: 'filterme')
+
+            control = ActiveRecord::QueryRecorder.new { get_filtered_list }
+
+            matched_project.update!(namespace: public_subgroup)
+
+            expect { get_filtered_list }.not_to exceed_query_limit(control).with_threshold(extra_queries_for_hierarchies)
+          end
+        end
+      end
+    end
+
+    context 'pagination' do
+      let(:per_page) { 3 }
+
+      before do
+        allow(Kaminari.config).to receive(:default_per_page).and_return(per_page)
+      end
+
+      context 'with only projects' do
+        let!(:other_project) { create(:project, :public, namespace: group) }
+        let!(:first_page_projects) { create_list(:project, per_page, :public, namespace: group ) }
+
+        it 'has projects on the first page' do
+          get :index, group_id: group.to_param, sort: 'id_desc', format: :json
+
+          expect(assigns(:children)).to contain_exactly(*first_page_projects)
+        end
+
+        it 'has projects on the second page' do
+          get :index, group_id: group.to_param, sort: 'id_desc', page: 2, format: :json
+
+          expect(assigns(:children)).to contain_exactly(other_project)
+        end
+      end
+
+      context 'with subgroups and projects', :nested_groups do
+        let!(:first_page_subgroups) { create_list(:group,  per_page, :public,  parent: group) }
+        let!(:other_subgroup) { create(:group, :public, parent: group) }
+        let!(:next_page_projects) { create_list(:project, per_page, :public, namespace: group) }
+
+        it 'contains all subgroups' do
+          get :index, group_id: group.to_param, sort: 'id_asc', format: :json
+
+          expect(assigns(:children)).to contain_exactly(*first_page_subgroups)
+        end
+
+        it 'contains the project and group on the second page' do
+          get :index, group_id: group.to_param, sort: 'id_asc', page: 2, format: :json
+
+          expect(assigns(:children)).to contain_exactly(other_subgroup, *next_page_projects.take(per_page - 1))
+        end
+      end
+    end
+  end
+end
diff --git a/spec/controllers/groups_controller_spec.rb b/spec/controllers/groups_controller_spec.rb
index b0564e27a68..e7631d4d709 100644
--- a/spec/controllers/groups_controller_spec.rb
+++ b/spec/controllers/groups_controller_spec.rb
@@ -1,4 +1,4 @@
-require 'rails_helper'
+require 'spec_helper'
 
 describe GroupsController do
   let(:user) { create(:user) }
@@ -150,42 +150,6 @@ describe GroupsController do
     end
   end
 
-  describe 'GET #subgroups', :nested_groups do
-    let!(:public_subgroup) { create(:group, :public, parent: group) }
-    let!(:private_subgroup) { create(:group, :private, parent: group) }
-
-    context 'as a user' do
-      before do
-        sign_in(user)
-      end
-
-      it 'shows all subgroups' do
-        get :subgroups, id: group.to_param
-
-        expect(assigns(:nested_groups)).to contain_exactly(public_subgroup, private_subgroup)
-      end
-
-      context 'being member of private subgroup' do
-        it 'shows public and private subgroups the user is member of' do
-          group_member.destroy!
-          private_subgroup.add_guest(user)
-
-          get :subgroups, id: group.to_param
-
-          expect(assigns(:nested_groups)).to contain_exactly(public_subgroup, private_subgroup)
-        end
-      end
-    end
-
-    context 'as a guest' do
-      it 'shows the public subgroups' do
-        get :subgroups, id: group.to_param
-
-        expect(assigns(:nested_groups)).to contain_exactly(public_subgroup)
-      end
-    end
-  end
-
   describe 'GET #issues' do
     let(:issue_1) { create(:issue, project: project) }
     let(:issue_2) { create(:issue, project: project) }
@@ -425,62 +389,62 @@ describe GroupsController do
           end
         end
       end
-    end
 
-    context 'for a POST request' do
-      context 'when requesting the canonical path with different casing' do
-        it 'does not 404' do
-          post :update, id: group.to_param.upcase, group: { path: 'new_path' }
+      context 'for a POST request' do
+        context 'when requesting the canonical path with different casing' do
+          it 'does not 404' do
+            post :update, id: group.to_param.upcase, group: { path: 'new_path' }
 
-          expect(response).not_to have_http_status(404)
-        end
+            expect(response).not_to have_http_status(404)
+          end
 
-        it 'does not redirect to the correct casing' do
-          post :update, id: group.to_param.upcase, group: { path: 'new_path' }
+          it 'does not redirect to the correct casing' do
+            post :update, id: group.to_param.upcase, group: { path: 'new_path' }
 
-          expect(response).not_to have_http_status(301)
+            expect(response).not_to have_http_status(301)
+          end
         end
-      end
 
-      context 'when requesting a redirected path' do
-        let(:redirect_route) { group.redirect_routes.create(path: 'old-path') }
+        context 'when requesting a redirected path' do
+          let(:redirect_route) { group.redirect_routes.create(path: 'old-path') }
 
-        it 'returns not found' do
-          post :update, id: redirect_route.path, group: { path: 'new_path' }
+          it 'returns not found' do
+            post :update, id: redirect_route.path, group: { path: 'new_path' }
 
-          expect(response).to have_http_status(404)
+            expect(response).to have_http_status(404)
+          end
         end
       end
-    end
 
-    context 'for a DELETE request' do
-      context 'when requesting the canonical path with different casing' do
-        it 'does not 404' do
-          delete :destroy, id: group.to_param.upcase
+      context 'for a DELETE request' do
+        context 'when requesting the canonical path with different casing' do
+          it 'does not 404' do
+            delete :destroy, id: group.to_param.upcase
 
-          expect(response).not_to have_http_status(404)
-        end
+            expect(response).not_to have_http_status(404)
+          end
 
-        it 'does not redirect to the correct casing' do
-          delete :destroy, id: group.to_param.upcase
+          it 'does not redirect to the correct casing' do
+            delete :destroy, id: group.to_param.upcase
 
-          expect(response).not_to have_http_status(301)
+            expect(response).not_to have_http_status(301)
+          end
         end
-      end
 
-      context 'when requesting a redirected path' do
-        let(:redirect_route) { group.redirect_routes.create(path: 'old-path') }
+        context 'when requesting a redirected path' do
+          let(:redirect_route) { group.redirect_routes.create(path: 'old-path') }
 
-        it 'returns not found' do
-          delete :destroy, id: redirect_route.path
+          it 'returns not found' do
+            delete :destroy, id: redirect_route.path
 
-          expect(response).to have_http_status(404)
+            expect(response).to have_http_status(404)
+          end
         end
       end
     end
-  end
 
-  def group_moved_message(redirect_route, group)
-    "Group '#{redirect_route.path}' was moved to '#{group.full_path}'. Please update any links and bookmarks that may still have the old path."
+    def group_moved_message(redirect_route, group)
+      "Group '#{redirect_route.path}' was moved to '#{group.full_path}'. Please update any links and bookmarks that may still have the old path."
+    end
   end
 end
diff --git a/spec/features/dashboard/groups_list_spec.rb b/spec/features/dashboard/groups_list_spec.rb
index a6329b5c78d..c6873d1923c 100644
--- a/spec/features/dashboard/groups_list_spec.rb
+++ b/spec/features/dashboard/groups_list_spec.rb
@@ -6,6 +6,13 @@ feature 'Dashboard Groups page', :js do
   let(:nested_group) { create(:group, :nested) }
   let(:another_group) { create(:group) }
 
+  def click_group_caret(group)
+    within("#group-#{group.id}") do
+      first('.folder-caret').click
+    end
+    wait_for_requests
+  end
+
   it 'shows groups user is member of' do
     group.add_owner(user)
     nested_group.add_owner(user)
@@ -13,13 +20,27 @@ feature 'Dashboard Groups page', :js do
 
     sign_in(user)
     visit dashboard_groups_path
+    wait_for_requests
+
+    expect(page).to have_content(group.name)
+
+    expect(page).not_to have_content(another_group.name)
+  end
+
+  it 'shows subgroups the user is member of', :nested_groups do
+    group.add_owner(user)
+    nested_group.add_owner(user)
+
+    sign_in(user)
+    visit dashboard_groups_path
+    wait_for_requests
 
-    expect(page).to have_content(group.full_name)
-    expect(page).to have_content(nested_group.full_name)
-    expect(page).not_to have_content(another_group.full_name)
+    expect(page).to have_content(nested_group.parent.name)
+    click_group_caret(nested_group.parent)
+    expect(page).to have_content(nested_group.name)
   end
 
-  describe 'when filtering groups' do
+  describe 'when filtering groups', :nested_groups do
     before do
       group.add_owner(user)
       nested_group.add_owner(user)
@@ -30,25 +51,26 @@ feature 'Dashboard Groups page', :js do
       visit dashboard_groups_path
     end
 
-    it 'filters groups' do
-      fill_in 'filter_groups', with: group.name
+    it 'expands when filtering groups' do
+      fill_in 'filter', with: nested_group.name
       wait_for_requests
 
-      expect(page).to have_content(group.full_name)
-      expect(page).not_to have_content(nested_group.full_name)
-      expect(page).not_to have_content(another_group.full_name)
+      expect(page).not_to have_content(group.name)
+      expect(page).to have_content(nested_group.parent.name)
+      expect(page).to have_content(nested_group.name)
+      expect(page).not_to have_content(another_group.name)
     end
 
     it 'resets search when user cleans the input' do
-      fill_in 'filter_groups', with: group.name
+      fill_in 'filter', with: group.name
       wait_for_requests
 
-      fill_in 'filter_groups', with: ''
+      fill_in 'filter', with: ''
       wait_for_requests
 
-      expect(page).to have_content(group.full_name)
-      expect(page).to have_content(nested_group.full_name)
-      expect(page).not_to have_content(another_group.full_name)
+      expect(page).to have_content(group.name)
+      expect(page).to have_content(nested_group.parent.name)
+      expect(page).not_to have_content(another_group.name)
       expect(page.all('.js-groups-list-holder .content-list li').length).to eq 2
     end
   end
@@ -66,28 +88,29 @@ feature 'Dashboard Groups page', :js do
     end
 
     it 'shows subgroups inside of its parent group' do
-      expect(page).to have_selector('.groups-list-tree-container .group-list-tree', count: 2)
-      expect(page).to have_selector(".groups-list-tree-container #group-#{group.id} #group-#{subgroup.id}", count: 1)
+      expect(page).to have_selector("#group-#{group.id}")
+      click_group_caret(group)
+      expect(page).to have_selector("#group-#{group.id} #group-#{subgroup.id}")
     end
 
     it 'can toggle parent group' do
-      # Expanded by default
-      expect(page).to have_selector("#group-#{group.id} .fa-caret-down", count: 1)
-      expect(page).not_to have_selector("#group-#{group.id} .fa-caret-right")
+      # Collapsed by default
+      expect(page).not_to have_selector("#group-#{group.id} .fa-caret-down", count: 1)
+      expect(page).to have_selector("#group-#{group.id} .fa-caret-right")
 
-      # Collapse
-      find("#group-#{group.id}").trigger('click')
+      # expand
+      click_group_caret(group)
 
-      expect(page).not_to have_selector("#group-#{group.id} .fa-caret-down")
-      expect(page).to have_selector("#group-#{group.id} .fa-caret-right", count: 1)
-      expect(page).not_to have_selector("#group-#{group.id} #group-#{subgroup.id}")
+      expect(page).to have_selector("#group-#{group.id} .fa-caret-down")
+      expect(page).not_to have_selector("#group-#{group.id} .fa-caret-right", count: 1)
+      expect(page).to have_selector("#group-#{group.id} #group-#{subgroup.id}")
 
-      # Expand
-      find("#group-#{group.id}").trigger('click')
+      # collapse
+      click_group_caret(group)
 
-      expect(page).to have_selector("#group-#{group.id} .fa-caret-down", count: 1)
-      expect(page).not_to have_selector("#group-#{group.id} .fa-caret-right")
-      expect(page).to have_selector("#group-#{group.id} #group-#{subgroup.id}")
+      expect(page).not_to have_selector("#group-#{group.id} .fa-caret-down", count: 1)
+      expect(page).to have_selector("#group-#{group.id} .fa-caret-right")
+      expect(page).not_to have_selector("#group-#{group.id} #group-#{subgroup.id}")
     end
   end
 
diff --git a/spec/features/explore/groups_list_spec.rb b/spec/features/explore/groups_list_spec.rb
index b5325301968..801a33979ff 100644
--- a/spec/features/explore/groups_list_spec.rb
+++ b/spec/features/explore/groups_list_spec.rb
@@ -13,6 +13,7 @@ describe 'Explore Groups page', :js do
     sign_in(user)
 
     visit explore_groups_path
+    wait_for_requests
   end
 
   it 'shows groups user is member of' do
@@ -22,7 +23,7 @@ describe 'Explore Groups page', :js do
   end
 
   it 'filters groups' do
-    fill_in 'filter_groups', with: group.name
+    fill_in 'filter', with: group.name
     wait_for_requests
 
     expect(page).to have_content(group.full_name)
@@ -31,10 +32,10 @@ describe 'Explore Groups page', :js do
   end
 
   it 'resets search when user cleans the input' do
-    fill_in 'filter_groups', with: group.name
+    fill_in 'filter', with: group.name
     wait_for_requests
 
-    fill_in 'filter_groups', with: ""
+    fill_in 'filter', with: ""
     wait_for_requests
 
     expect(page).to have_content(group.full_name)
@@ -45,21 +46,21 @@ describe 'Explore Groups page', :js do
 
   it 'shows non-archived projects count' do
     # Initially project is not archived
-    expect(find('.js-groups-list-holder .content-list li:first-child .stats span:first-child')).to have_text("1")
+    expect(find('.js-groups-list-holder .content-list li:first-child .stats .number-projects')).to have_text("1")
 
     # Archive project
     empty_project.archive!
     visit explore_groups_path
 
     # Check project count
-    expect(find('.js-groups-list-holder .content-list li:first-child .stats span:first-child')).to have_text("0")
+    expect(find('.js-groups-list-holder .content-list li:first-child .stats .number-projects')).to have_text("0")
 
     # Unarchive project
     empty_project.unarchive!
     visit explore_groups_path
 
     # Check project count
-    expect(find('.js-groups-list-holder .content-list li:first-child .stats span:first-child')).to have_text("1")
+    expect(find('.js-groups-list-holder .content-list li:first-child .stats .number-projects')).to have_text("1")
   end
 
   describe 'landing component' do
diff --git a/spec/features/groups/show_spec.rb b/spec/features/groups/show_spec.rb
index 303013e59d5..7fc2b383749 100644
--- a/spec/features/groups/show_spec.rb
+++ b/spec/features/groups/show_spec.rb
@@ -24,4 +24,35 @@ feature 'Group show page' do
 
     it_behaves_like "an autodiscoverable RSS feed without an RSS token"
   end
+
+  context 'subgroup support' do
+    let(:user) { create(:user) }
+
+    before do
+      group.add_owner(user)
+      sign_in(user)
+    end
+
+    context 'when subgroups are supported', :js, :nested_groups do
+      before do
+        allow(Group).to receive(:supports_nested_groups?) { true }
+        visit path
+      end
+
+      it 'allows creating subgroups' do
+        expect(page).to have_css("li[data-text='New subgroup']", visible: false)
+      end
+    end
+
+    context 'when subgroups are not supported' do
+      before do
+        allow(Group).to receive(:supports_nested_groups?) { false }
+        visit path
+      end
+
+      it 'allows creating subgroups' do
+        expect(page).not_to have_selector("li[data-text='New subgroup']", visible: false)
+      end
+    end
+  end
 end
diff --git a/spec/features/groups_spec.rb b/spec/features/groups_spec.rb
index 862823d862e..cc8906fa969 100644
--- a/spec/features/groups_spec.rb
+++ b/spec/features/groups_spec.rb
@@ -90,8 +90,7 @@ feature 'Group' do
 
     context 'as admin' do
       before do
-        visit subgroups_group_path(group)
-        click_link 'New Subgroup'
+        visit new_group_path(group, parent_id: group.id)
       end
 
       it 'creates a nested group' do
@@ -111,8 +110,8 @@ feature 'Group' do
         sign_out(:user)
         sign_in(user)
 
-        visit subgroups_group_path(group)
-        click_link 'New Subgroup'
+        visit new_group_path(group, parent_id: group.id)
+
         fill_in 'Group path', with: 'bar'
         click_button 'Create group'
 
@@ -120,16 +119,6 @@ feature 'Group' do
         expect(page).to have_content("Group 'bar' was successfully created.")
       end
     end
-
-    context 'when nested group feature is disabled' do
-      it 'renders 404' do
-        allow(Group).to receive(:supports_nested_groups?).and_return(false)
-
-        visit subgroups_group_path(group)
-
-        expect(page.status_code).to eq(404)
-      end
-    end
   end
 
   it 'checks permissions to avoid exposing groups by parent_id' do
@@ -210,13 +199,15 @@ feature 'Group' do
   describe 'group page with nested groups', :nested_groups, :js do
     let!(:group) { create(:group) }
     let!(:nested_group) { create(:group, parent: group) }
+    let!(:project) { create(:project, namespace: group) }
     let!(:path)  { group_path(group) }
 
-    it 'has nested groups tab with nested groups inside' do
+    it 'it renders projects and groups on the page' do
       visit path
-      click_link 'Subgroups'
+      wait_for_requests
 
       expect(page).to have_content(nested_group.name)
+      expect(page).to have_content(project.name)
     end
   end
 
diff --git a/spec/finders/group_descendants_finder_spec.rb b/spec/finders/group_descendants_finder_spec.rb
new file mode 100644
index 00000000000..074914420a1
--- /dev/null
+++ b/spec/finders/group_descendants_finder_spec.rb
@@ -0,0 +1,166 @@
+require 'spec_helper'
+
+describe GroupDescendantsFinder do
+  let(:user) { create(:user) }
+  let(:group) { create(:group) }
+  let(:params) { {} }
+  subject(:finder) do
+    described_class.new(current_user: user, parent_group: group, params: params)
+  end
+
+  before do
+    group.add_owner(user)
+  end
+
+  describe '#has_children?' do
+    it 'is true when there are projects' do
+      create(:project, namespace: group)
+
+      expect(finder.has_children?).to be_truthy
+    end
+
+    context 'when there are subgroups', :nested_groups do
+      it 'is true when there are projects' do
+        create(:group, parent: group)
+
+        expect(finder.has_children?).to be_truthy
+      end
+    end
+  end
+
+  describe '#execute' do
+    it 'includes projects' do
+      project = create(:project, namespace: group)
+
+      expect(finder.execute).to contain_exactly(project)
+    end
+
+    context 'when archived is `true`' do
+      let(:params) { { archived: 'true' } }
+
+      it 'includes archived projects' do
+        archived_project = create(:project, namespace: group, archived: true)
+        project = create(:project, namespace: group)
+
+        expect(finder.execute).to contain_exactly(archived_project, project)
+      end
+    end
+
+    context 'when archived is `only`' do
+      let(:params) { { archived: 'only' } }
+
+      it 'includes only archived projects' do
+        archived_project = create(:project, namespace: group, archived: true)
+        _project = create(:project, namespace: group)
+
+        expect(finder.execute).to contain_exactly(archived_project)
+      end
+    end
+
+    it 'does not include archived projects' do
+      _archived_project = create(:project, :archived, namespace: group)
+
+      expect(finder.execute).to be_empty
+    end
+
+    context 'with a filter' do
+      let(:params) { { filter: 'test' } }
+
+      it 'includes only projects matching the filter' do
+        _other_project = create(:project, namespace: group)
+        matching_project = create(:project, namespace: group, name: 'testproject')
+
+        expect(finder.execute).to contain_exactly(matching_project)
+      end
+    end
+  end
+
+  context 'with nested groups', :nested_groups do
+    let!(:project) { create(:project, namespace: group) }
+    let!(:subgroup) { create(:group, :private, parent: group) }
+
+    describe '#execute' do
+      it 'contains projects and subgroups' do
+        expect(finder.execute).to contain_exactly(subgroup, project)
+      end
+
+      it 'does not include subgroups the user does not have access to' do
+        subgroup.update!(visibility_level: Gitlab::VisibilityLevel::PRIVATE)
+
+        public_subgroup = create(:group, :public, parent: group, path: 'public-group')
+        other_subgroup = create(:group, :private, parent: group, path: 'visible-private-group')
+        other_user = create(:user)
+        other_subgroup.add_developer(other_user)
+
+        finder = described_class.new(current_user: other_user, parent_group: group)
+
+        expect(finder.execute).to contain_exactly(public_subgroup, other_subgroup)
+      end
+
+      it 'only includes public groups when no user is given' do
+        public_subgroup = create(:group, :public, parent: group)
+        _private_subgroup = create(:group, :private, parent: group)
+
+        finder = described_class.new(current_user: nil, parent_group: group)
+
+        expect(finder.execute).to contain_exactly(public_subgroup)
+      end
+
+      context 'when archived is `true`' do
+        let(:params) { { archived: 'true' } }
+
+        it 'includes archived projects in the count of subgroups' do
+          create(:project, namespace: subgroup, archived: true)
+
+          expect(finder.execute.first.preloaded_project_count).to eq(1)
+        end
+      end
+
+      context 'with a filter' do
+        let(:params) { { filter: 'test' } }
+
+        it 'contains only matching projects and subgroups' do
+          matching_project = create(:project, namespace: group, name: 'Testproject')
+          matching_subgroup = create(:group, name: 'testgroup', parent: group)
+
+          expect(finder.execute).to contain_exactly(matching_subgroup, matching_project)
+        end
+
+        it 'does not include subgroups the user does not have access to' do
+          _invisible_subgroup = create(:group, :private, parent: group, name: 'test1')
+          other_subgroup = create(:group, :private, parent: group, name: 'test2')
+          public_subgroup = create(:group, :public, parent: group, name: 'test3')
+          other_subsubgroup = create(:group, :private, parent: other_subgroup, name: 'test4')
+          other_user = create(:user)
+          other_subgroup.add_developer(other_user)
+
+          finder = described_class.new(current_user: other_user,
+                                       parent_group: group,
+                                       params: params)
+
+          expect(finder.execute).to contain_exactly(other_subgroup, public_subgroup, other_subsubgroup)
+        end
+
+        context 'with matching children' do
+          it 'includes a group that has a subgroup matching the query and its parent' do
+            matching_subgroup = create(:group, :private, name: 'testgroup', parent: subgroup)
+
+            expect(finder.execute).to contain_exactly(subgroup, matching_subgroup)
+          end
+
+          it 'includes the parent of a matching project' do
+            matching_project = create(:project, namespace: subgroup, name: 'Testproject')
+
+            expect(finder.execute).to contain_exactly(subgroup, matching_project)
+          end
+
+          it 'does not include the parent itself' do
+            group.update!(name: 'test')
+
+            expect(finder.execute).not_to include(group)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/javascripts/groups/components/app_spec.js b/spec/javascripts/groups/components/app_spec.js
new file mode 100644
index 00000000000..cd19a0fae1e
--- /dev/null
+++ b/spec/javascripts/groups/components/app_spec.js
@@ -0,0 +1,443 @@
+import Vue from 'vue';
+
+import appComponent from '~/groups/components/app.vue';
+import groupFolderComponent from '~/groups/components/group_folder.vue';
+import groupItemComponent from '~/groups/components/group_item.vue';
+
+import eventHub from '~/groups/event_hub';
+import GroupsStore from '~/groups/store/groups_store';
+import GroupsService from '~/groups/service/groups_service';
+
+import {
+  mockEndpoint, mockGroups, mockSearchedGroups,
+  mockRawPageInfo, mockParentGroupItem, mockRawChildren,
+  mockChildren, mockPageInfo,
+} from '../mock_data';
+
+const createComponent = (hideProjects = false) => {
+  const Component = Vue.extend(appComponent);
+  const store = new GroupsStore(false);
+  const service = new GroupsService(mockEndpoint);
+
+  return new Component({
+    propsData: {
+      store,
+      service,
+      hideProjects,
+    },
+  });
+};
+
+const returnServicePromise = (data, failed) => new Promise((resolve, reject) => {
+  if (failed) {
+    reject(data);
+  } else {
+    resolve({
+      json() {
+        return data;
+      },
+    });
+  }
+});
+
+describe('AppComponent', () => {
+  let vm;
+
+  beforeEach((done) => {
+    Vue.component('group-folder', groupFolderComponent);
+    Vue.component('group-item', groupItemComponent);
+
+    vm = createComponent();
+
+    Vue.nextTick(() => {
+      done();
+    });
+  });
+
+  describe('computed', () => {
+    beforeEach(() => {
+      vm.$mount();
+    });
+
+    afterEach(() => {
+      vm.$destroy();
+    });
+
+    describe('groups', () => {
+      it('should return list of groups from store', () => {
+        spyOn(vm.store, 'getGroups');
+
+        const groups = vm.groups;
+        expect(vm.store.getGroups).toHaveBeenCalled();
+        expect(groups).not.toBeDefined();
+      });
+    });
+
+    describe('pageInfo', () => {
+      it('should return pagination info from store', () => {
+        spyOn(vm.store, 'getPaginationInfo');
+
+        const pageInfo = vm.pageInfo;
+        expect(vm.store.getPaginationInfo).toHaveBeenCalled();
+        expect(pageInfo).not.toBeDefined();
+      });
+    });
+  });
+
+  describe('methods', () => {
+    beforeEach(() => {
+      vm.$mount();
+    });
+
+    afterEach(() => {
+      vm.$destroy();
+    });
+
+    describe('fetchGroups', () => {
+      it('should call `getGroups` with all the params provided', (done) => {
+        spyOn(vm.service, 'getGroups').and.returnValue(returnServicePromise(mockGroups));
+
+        vm.fetchGroups({
+          parentId: 1,
+          page: 2,
+          filterGroupsBy: 'git',
+          sortBy: 'created_desc',
+          archived: true,
+        });
+        setTimeout(() => {
+          expect(vm.service.getGroups).toHaveBeenCalledWith(1, 2, 'git', 'created_desc', true);
+          done();
+        }, 0);
+      });
+
+      it('should set headers to store for building pagination info when called with `updatePagination`', (done) => {
+        spyOn(vm.service, 'getGroups').and.returnValue(returnServicePromise({ headers: mockRawPageInfo }));
+        spyOn(vm, 'updatePagination');
+
+        vm.fetchGroups({ updatePagination: true });
+        setTimeout(() => {
+          expect(vm.service.getGroups).toHaveBeenCalled();
+          expect(vm.updatePagination).toHaveBeenCalled();
+          done();
+        }, 0);
+      });
+
+      it('should show flash error when request fails', (done) => {
+        spyOn(vm.service, 'getGroups').and.returnValue(returnServicePromise(null, true));
+        spyOn($, 'scrollTo');
+        spyOn(window, 'Flash');
+
+        vm.fetchGroups({});
+        setTimeout(() => {
+          expect(vm.isLoading).toBeFalsy();
+          expect($.scrollTo).toHaveBeenCalledWith(0);
+          expect(window.Flash).toHaveBeenCalledWith('An error occurred. Please try again.');
+          done();
+        }, 0);
+      });
+    });
+
+    describe('fetchAllGroups', () => {
+      it('should fetch default set of groups', (done) => {
+        spyOn(vm, 'fetchGroups').and.returnValue(returnServicePromise(mockGroups));
+        spyOn(vm, 'updatePagination').and.callThrough();
+        spyOn(vm, 'updateGroups').and.callThrough();
+
+        vm.fetchAllGroups();
+        expect(vm.isLoading).toBeTruthy();
+        expect(vm.fetchGroups).toHaveBeenCalled();
+        setTimeout(() => {
+          expect(vm.isLoading).toBeFalsy();
+          expect(vm.updateGroups).toHaveBeenCalled();
+          done();
+        }, 0);
+      });
+
+      it('should fetch matching set of groups when app is loaded with search query', (done) => {
+        spyOn(vm, 'fetchGroups').and.returnValue(returnServicePromise(mockSearchedGroups));
+        spyOn(vm, 'updateGroups').and.callThrough();
+
+        vm.fetchAllGroups();
+        expect(vm.fetchGroups).toHaveBeenCalledWith({
+          page: null,
+          filterGroupsBy: null,
+          sortBy: null,
+          updatePagination: true,
+          archived: null,
+        });
+        setTimeout(() => {
+          expect(vm.updateGroups).toHaveBeenCalled();
+          done();
+        }, 0);
+      });
+    });
+
+    describe('fetchPage', () => {
+      it('should fetch groups for provided page details and update window state', (done) => {
+        spyOn(vm, 'fetchGroups').and.returnValue(returnServicePromise(mockGroups));
+        spyOn(vm, 'updateGroups').and.callThrough();
+        spyOn(gl.utils, 'mergeUrlParams').and.callThrough();
+        spyOn(window.history, 'replaceState');
+        spyOn($, 'scrollTo');
+
+        vm.fetchPage(2, null, null, true);
+        expect(vm.isLoading).toBeTruthy();
+        expect(vm.fetchGroups).toHaveBeenCalledWith({
+          page: 2,
+          filterGroupsBy: null,
+          sortBy: null,
+          updatePagination: true,
+          archived: true,
+        });
+        setTimeout(() => {
+          expect(vm.isLoading).toBeFalsy();
+          expect($.scrollTo).toHaveBeenCalledWith(0);
+          expect(gl.utils.mergeUrlParams).toHaveBeenCalledWith({ page: 2 }, jasmine.any(String));
+          expect(window.history.replaceState).toHaveBeenCalledWith({
+            page: jasmine.any(String),
+          }, jasmine.any(String), jasmine.any(String));
+          expect(vm.updateGroups).toHaveBeenCalled();
+          done();
+        }, 0);
+      });
+    });
+
+    describe('toggleChildren', () => {
+      let groupItem;
+
+      beforeEach(() => {
+        groupItem = Object.assign({}, mockParentGroupItem);
+        groupItem.isOpen = false;
+        groupItem.isChildrenLoading = false;
+      });
+
+      it('should fetch children of given group and expand it if group is collapsed and children are not loaded', (done) => {
+        spyOn(vm, 'fetchGroups').and.returnValue(returnServicePromise(mockRawChildren));
+        spyOn(vm.store, 'setGroupChildren');
+
+        vm.toggleChildren(groupItem);
+        expect(groupItem.isChildrenLoading).toBeTruthy();
+        expect(vm.fetchGroups).toHaveBeenCalledWith({
+          parentId: groupItem.id,
+        });
+        setTimeout(() => {
+          expect(vm.store.setGroupChildren).toHaveBeenCalled();
+          done();
+        }, 0);
+      });
+
+      it('should skip network request while expanding group if children are already loaded', () => {
+        spyOn(vm, 'fetchGroups');
+        groupItem.children = mockRawChildren;
+
+        vm.toggleChildren(groupItem);
+        expect(vm.fetchGroups).not.toHaveBeenCalled();
+        expect(groupItem.isOpen).toBeTruthy();
+      });
+
+      it('should collapse group if it is already expanded', () => {
+        spyOn(vm, 'fetchGroups');
+        groupItem.isOpen = true;
+
+        vm.toggleChildren(groupItem);
+        expect(vm.fetchGroups).not.toHaveBeenCalled();
+        expect(groupItem.isOpen).toBeFalsy();
+      });
+
+      it('should set `isChildrenLoading` back to `false` if load request fails', (done) => {
+        spyOn(vm, 'fetchGroups').and.returnValue(returnServicePromise({}, true));
+
+        vm.toggleChildren(groupItem);
+        expect(groupItem.isChildrenLoading).toBeTruthy();
+        setTimeout(() => {
+          expect(groupItem.isChildrenLoading).toBeFalsy();
+          done();
+        }, 0);
+      });
+    });
+
+    describe('leaveGroup', () => {
+      let groupItem;
+      let childGroupItem;
+
+      beforeEach(() => {
+        groupItem = Object.assign({}, mockParentGroupItem);
+        groupItem.children = mockChildren;
+        childGroupItem = groupItem.children[0];
+        groupItem.isChildrenLoading = false;
+      });
+
+      it('should leave group and remove group item from tree', (done) => {
+        const notice = `You left the "${childGroupItem.fullName}" group.`;
+        spyOn(vm.service, 'leaveGroup').and.returnValue(returnServicePromise({ notice }));
+        spyOn(vm.store, 'removeGroup').and.callThrough();
+        spyOn(window, 'Flash');
+        spyOn($, 'scrollTo');
+
+        vm.leaveGroup(childGroupItem, groupItem);
+        expect(childGroupItem.isBeingRemoved).toBeTruthy();
+        expect(vm.service.leaveGroup).toHaveBeenCalledWith(childGroupItem.leavePath);
+        setTimeout(() => {
+          expect($.scrollTo).toHaveBeenCalledWith(0);
+          expect(vm.store.removeGroup).toHaveBeenCalledWith(childGroupItem, groupItem);
+          expect(window.Flash).toHaveBeenCalledWith(notice, 'notice');
+          done();
+        }, 0);
+      });
+
+      it('should show error flash message if request failed to leave group', (done) => {
+        const message = 'An error occurred. Please try again.';
+        spyOn(vm.service, 'leaveGroup').and.returnValue(returnServicePromise({ status: 500 }, true));
+        spyOn(vm.store, 'removeGroup').and.callThrough();
+        spyOn(window, 'Flash');
+
+        vm.leaveGroup(childGroupItem, groupItem);
+        expect(childGroupItem.isBeingRemoved).toBeTruthy();
+        expect(vm.service.leaveGroup).toHaveBeenCalledWith(childGroupItem.leavePath);
+        setTimeout(() => {
+          expect(vm.store.removeGroup).not.toHaveBeenCalled();
+          expect(window.Flash).toHaveBeenCalledWith(message);
+          expect(childGroupItem.isBeingRemoved).toBeFalsy();
+          done();
+        }, 0);
+      });
+
+      it('should show appropriate error flash message if request forbids to leave group', (done) => {
+        const message = 'Failed to leave the group. Please make sure you are not the only owner.';
+        spyOn(vm.service, 'leaveGroup').and.returnValue(returnServicePromise({ status: 403 }, true));
+        spyOn(vm.store, 'removeGroup').and.callThrough();
+        spyOn(window, 'Flash');
+
+        vm.leaveGroup(childGroupItem, groupItem);
+        expect(childGroupItem.isBeingRemoved).toBeTruthy();
+        expect(vm.service.leaveGroup).toHaveBeenCalledWith(childGroupItem.leavePath);
+        setTimeout(() => {
+          expect(vm.store.removeGroup).not.toHaveBeenCalled();
+          expect(window.Flash).toHaveBeenCalledWith(message);
+          expect(childGroupItem.isBeingRemoved).toBeFalsy();
+          done();
+        }, 0);
+      });
+    });
+
+    describe('updatePagination', () => {
+      it('should set pagination info to store from provided headers', () => {
+        spyOn(vm.store, 'setPaginationInfo');
+
+        vm.updatePagination(mockRawPageInfo);
+        expect(vm.store.setPaginationInfo).toHaveBeenCalledWith(mockRawPageInfo);
+      });
+    });
+
+    describe('updateGroups', () => {
+      it('should call setGroups on store if method was called directly', () => {
+        spyOn(vm.store, 'setGroups');
+
+        vm.updateGroups(mockGroups);
+        expect(vm.store.setGroups).toHaveBeenCalledWith(mockGroups);
+      });
+
+      it('should call setSearchedGroups on store if method was called with fromSearch param', () => {
+        spyOn(vm.store, 'setSearchedGroups');
+
+        vm.updateGroups(mockGroups, true);
+        expect(vm.store.setSearchedGroups).toHaveBeenCalledWith(mockGroups);
+      });
+
+      it('should set `isSearchEmpty` prop based on groups count', () => {
+        vm.updateGroups(mockGroups);
+        expect(vm.isSearchEmpty).toBeFalsy();
+
+        vm.updateGroups([]);
+        expect(vm.isSearchEmpty).toBeTruthy();
+      });
+    });
+  });
+
+  describe('created', () => {
+    it('should bind event listeners on eventHub', (done) => {
+      spyOn(eventHub, '$on');
+
+      const newVm = createComponent();
+      newVm.$mount();
+
+      Vue.nextTick(() => {
+        expect(eventHub.$on).toHaveBeenCalledWith('fetchPage', jasmine.any(Function));
+        expect(eventHub.$on).toHaveBeenCalledWith('toggleChildren', jasmine.any(Function));
+        expect(eventHub.$on).toHaveBeenCalledWith('leaveGroup', jasmine.any(Function));
+        expect(eventHub.$on).toHaveBeenCalledWith('updatePagination', jasmine.any(Function));
+        expect(eventHub.$on).toHaveBeenCalledWith('updateGroups', jasmine.any(Function));
+        newVm.$destroy();
+        done();
+      });
+    });
+
+    it('should initialize `searchEmptyMessage` prop with correct string when `hideProjects` is `false`', (done) => {
+      const newVm = createComponent();
+      newVm.$mount();
+      Vue.nextTick(() => {
+        expect(newVm.searchEmptyMessage).toBe('Sorry, no groups or projects matched your search');
+        newVm.$destroy();
+        done();
+      });
+    });
+
+    it('should initialize `searchEmptyMessage` prop with correct string when `hideProjects` is `true`', (done) => {
+      const newVm = createComponent(true);
+      newVm.$mount();
+      Vue.nextTick(() => {
+        expect(newVm.searchEmptyMessage).toBe('Sorry, no groups matched your search');
+        newVm.$destroy();
+        done();
+      });
+    });
+  });
+
+  describe('beforeDestroy', () => {
+    it('should unbind event listeners on eventHub', (done) => {
+      spyOn(eventHub, '$off');
+
+      const newVm = createComponent();
+      newVm.$mount();
+      newVm.$destroy();
+
+      Vue.nextTick(() => {
+        expect(eventHub.$off).toHaveBeenCalledWith('fetchPage', jasmine.any(Function));
+        expect(eventHub.$off).toHaveBeenCalledWith('toggleChildren', jasmine.any(Function));
+        expect(eventHub.$off).toHaveBeenCalledWith('leaveGroup', jasmine.any(Function));
+        expect(eventHub.$off).toHaveBeenCalledWith('updatePagination', jasmine.any(Function));
+        expect(eventHub.$off).toHaveBeenCalledWith('updateGroups', jasmine.any(Function));
+        done();
+      });
+    });
+  });
+
+  describe('template', () => {
+    beforeEach(() => {
+      vm.$mount();
+    });
+
+    afterEach(() => {
+      vm.$destroy();
+    });
+
+    it('should render loading icon', (done) => {
+      vm.isLoading = true;
+      Vue.nextTick(() => {
+        expect(vm.$el.querySelector('.loading-animation')).toBeDefined();
+        expect(vm.$el.querySelector('i.fa').getAttribute('aria-label')).toBe('Loading groups');
+        done();
+      });
+    });
+
+    it('should render groups tree', (done) => {
+      vm.groups = [mockParentGroupItem];
+      vm.isLoading = false;
+      vm.pageInfo = mockPageInfo;
+      Vue.nextTick(() => {
+        expect(vm.$el.querySelector('.groups-list-tree-container')).toBeDefined();
+        done();
+      });
+    });
+  });
+});
diff --git a/spec/javascripts/groups/components/group_folder_spec.js b/spec/javascripts/groups/components/group_folder_spec.js
new file mode 100644
index 00000000000..4eb198595fb
--- /dev/null
+++ b/spec/javascripts/groups/components/group_folder_spec.js
@@ -0,0 +1,66 @@
+import Vue from 'vue';
+
+import groupFolderComponent from '~/groups/components/group_folder.vue';
+import groupItemComponent from '~/groups/components/group_item.vue';
+import { mockGroups, mockParentGroupItem } from '../mock_data';
+
+const createComponent = (groups = mockGroups, parentGroup = mockParentGroupItem) => {
+  const Component = Vue.extend(groupFolderComponent);
+
+  return new Component({
+    propsData: {
+      groups,
+      parentGroup,
+    },
+  });
+};
+
+describe('GroupFolderComponent', () => {
+  let vm;
+
+  beforeEach((done) => {
+    Vue.component('group-item', groupItemComponent);
+
+    vm = createComponent();
+    vm.$mount();
+
+    Vue.nextTick(() => {
+      done();
+    });
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('hasMoreChildren', () => {
+      it('should return false when childrenCount of group is less than MAX_CHILDREN_COUNT', () => {
+        expect(vm.hasMoreChildren).toBeFalsy();
+      });
+    });
+
+    describe('moreChildrenStats', () => {
+      it('should return message with count of excess children over MAX_CHILDREN_COUNT limit', () => {
+        expect(vm.moreChildrenStats).toBe('3 more items');
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('should render component template correctly', () => {
+      expect(vm.$el.classList.contains('group-list-tree')).toBeTruthy();
+      expect(vm.$el.querySelectorAll('li.group-row').length).toBe(7);
+    });
+
+    it('should render more children link when groups list has children over MAX_CHILDREN_COUNT limit', () => {
+      const parentGroup = Object.assign({}, mockParentGroupItem);
+      parentGroup.childrenCount = 21;
+
+      const newVm = createComponent(mockGroups, parentGroup);
+      newVm.$mount();
+      expect(newVm.$el.querySelector('li.group-row a.has-more-items')).toBeDefined();
+      newVm.$destroy();
+    });
+  });
+});
diff --git a/spec/javascripts/groups/components/group_item_spec.js b/spec/javascripts/groups/components/group_item_spec.js
new file mode 100644
index 00000000000..0f4fbdae445
--- /dev/null
+++ b/spec/javascripts/groups/components/group_item_spec.js
@@ -0,0 +1,177 @@
+import Vue from 'vue';
+
+import groupItemComponent from '~/groups/components/group_item.vue';
+import groupFolderComponent from '~/groups/components/group_folder.vue';
+import eventHub from '~/groups/event_hub';
+import { mockParentGroupItem, mockChildren } from '../mock_data';
+
+import mountComponent from '../../helpers/vue_mount_component_helper';
+
+const createComponent = (group = mockParentGroupItem, parentGroup = mockChildren[0]) => {
+  const Component = Vue.extend(groupItemComponent);
+
+  return mountComponent(Component, {
+    group,
+    parentGroup,
+  });
+};
+
+describe('GroupItemComponent', () => {
+  let vm;
+
+  beforeEach((done) => {
+    Vue.component('group-folder', groupFolderComponent);
+
+    vm = createComponent();
+
+    Vue.nextTick(() => {
+      done();
+    });
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('groupDomId', () => {
+      it('should return ID string suffixed with group ID', () => {
+        expect(vm.groupDomId).toBe('group-55');
+      });
+    });
+
+    describe('rowClass', () => {
+      it('should return map of classes based on group details', () => {
+        const classes = ['is-open', 'has-children', 'has-description', 'being-removed'];
+        const rowClass = vm.rowClass;
+
+        expect(Object.keys(rowClass).length).toBe(classes.length);
+        Object.keys(rowClass).forEach((className) => {
+          expect(classes.indexOf(className) > -1).toBeTruthy();
+        });
+      });
+    });
+
+    describe('hasChildren', () => {
+      it('should return boolean value representing if group has any children present', () => {
+        let newVm;
+        const group = Object.assign({}, mockParentGroupItem);
+
+        group.childrenCount = 5;
+        newVm = createComponent(group);
+        expect(newVm.hasChildren).toBeTruthy();
+        newVm.$destroy();
+
+        group.childrenCount = 0;
+        newVm = createComponent(group);
+        expect(newVm.hasChildren).toBeFalsy();
+        newVm.$destroy();
+      });
+    });
+
+    describe('hasAvatar', () => {
+      it('should return boolean value representing if group has any avatar present', () => {
+        let newVm;
+        const group = Object.assign({}, mockParentGroupItem);
+
+        group.avatarUrl = null;
+        newVm = createComponent(group);
+        expect(newVm.hasAvatar).toBeFalsy();
+        newVm.$destroy();
+
+        group.avatarUrl = '/uploads/group_avatar.png';
+        newVm = createComponent(group);
+        expect(newVm.hasAvatar).toBeTruthy();
+        newVm.$destroy();
+      });
+    });
+
+    describe('isGroup', () => {
+      it('should return boolean value representing if group item is of type `group` or not', () => {
+        let newVm;
+        const group = Object.assign({}, mockParentGroupItem);
+
+        group.type = 'group';
+        newVm = createComponent(group);
+        expect(newVm.isGroup).toBeTruthy();
+        newVm.$destroy();
+
+        group.type = 'project';
+        newVm = createComponent(group);
+        expect(newVm.isGroup).toBeFalsy();
+        newVm.$destroy();
+      });
+    });
+  });
+
+  describe('methods', () => {
+    describe('onClickRowGroup', () => {
+      let event;
+
+      beforeEach(() => {
+        const classList = {
+          contains() {
+            return false;
+          },
+        };
+
+        event = {
+          target: {
+            classList,
+            parentElement: {
+              classList,
+            },
+          },
+        };
+      });
+
+      it('should emit `toggleChildren` event when expand is clicked on a group and it has children present', () => {
+        spyOn(eventHub, '$emit');
+
+        vm.onClickRowGroup(event);
+        expect(eventHub.$emit).toHaveBeenCalledWith('toggleChildren', vm.group);
+      });
+
+      it('should navigate page to group homepage if group does not have any children present', (done) => {
+        const group = Object.assign({}, mockParentGroupItem);
+        group.childrenCount = 0;
+        const newVm = createComponent(group);
+        spyOn(gl.utils, 'visitUrl').and.stub();
+        spyOn(eventHub, '$emit');
+
+        newVm.onClickRowGroup(event);
+        setTimeout(() => {
+          expect(eventHub.$emit).not.toHaveBeenCalled();
+          expect(gl.utils.visitUrl).toHaveBeenCalledWith(newVm.group.relativePath);
+          done();
+        }, 0);
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('should render component template correctly', () => {
+      expect(vm.$el.getAttribute('id')).toBe('group-55');
+      expect(vm.$el.classList.contains('group-row')).toBeTruthy();
+
+      expect(vm.$el.querySelector('.group-row-contents')).toBeDefined();
+      expect(vm.$el.querySelector('.group-row-contents .controls')).toBeDefined();
+      expect(vm.$el.querySelector('.group-row-contents .stats')).toBeDefined();
+
+      expect(vm.$el.querySelector('.folder-toggle-wrap')).toBeDefined();
+      expect(vm.$el.querySelector('.folder-toggle-wrap .folder-caret')).toBeDefined();
+      expect(vm.$el.querySelector('.folder-toggle-wrap .item-type-icon')).toBeDefined();
+
+      expect(vm.$el.querySelector('.avatar-container')).toBeDefined();
+      expect(vm.$el.querySelector('.avatar-container a.no-expand')).toBeDefined();
+      expect(vm.$el.querySelector('.avatar-container .avatar')).toBeDefined();
+
+      expect(vm.$el.querySelector('.title')).toBeDefined();
+      expect(vm.$el.querySelector('.title a.no-expand')).toBeDefined();
+      expect(vm.$el.querySelector('.access-type')).toBeDefined();
+      expect(vm.$el.querySelector('.description')).toBeDefined();
+
+      expect(vm.$el.querySelector('.group-list-tree')).toBeDefined();
+    });
+  });
+});
diff --git a/spec/javascripts/groups/components/groups_spec.js b/spec/javascripts/groups/components/groups_spec.js
new file mode 100644
index 00000000000..90e818c1545
--- /dev/null
+++ b/spec/javascripts/groups/components/groups_spec.js
@@ -0,0 +1,70 @@
+import Vue from 'vue';
+
+import groupsComponent from '~/groups/components/groups.vue';
+import groupFolderComponent from '~/groups/components/group_folder.vue';
+import groupItemComponent from '~/groups/components/group_item.vue';
+import eventHub from '~/groups/event_hub';
+import { mockGroups, mockPageInfo } from '../mock_data';
+
+import mountComponent from '../../helpers/vue_mount_component_helper';
+
+const createComponent = (searchEmpty = false) => {
+  const Component = Vue.extend(groupsComponent);
+
+  return mountComponent(Component, {
+    groups: mockGroups,
+    pageInfo: mockPageInfo,
+    searchEmptyMessage: 'No matching results',
+    searchEmpty,
+  });
+};
+
+describe('GroupsComponent', () => {
+  let vm;
+
+  beforeEach((done) => {
+    Vue.component('group-folder', groupFolderComponent);
+    Vue.component('group-item', groupItemComponent);
+
+    vm = createComponent();
+
+    Vue.nextTick(() => {
+      done();
+    });
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('methods', () => {
+    describe('change', () => {
+      it('should emit `fetchPage` event when page is changed via pagination', () => {
+        spyOn(eventHub, '$emit').and.stub();
+
+        vm.change(2);
+        expect(eventHub.$emit).toHaveBeenCalledWith('fetchPage', 2, jasmine.any(Object), jasmine.any(Object), jasmine.any(Object));
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('should render component template correctly', (done) => {
+      Vue.nextTick(() => {
+        expect(vm.$el.querySelector('.groups-list-tree-container')).toBeDefined();
+        expect(vm.$el.querySelector('.group-list-tree')).toBeDefined();
+        expect(vm.$el.querySelector('.gl-pagination')).toBeDefined();
+        expect(vm.$el.querySelectorAll('.has-no-search-results').length === 0).toBeTruthy();
+        done();
+      });
+    });
+
+    it('should render empty search message when `searchEmpty` is `true`', (done) => {
+      vm.searchEmpty = true;
+      Vue.nextTick(() => {
+        expect(vm.$el.querySelector('.has-no-search-results')).toBeDefined();
+        done();
+      });
+    });
+  });
+});
diff --git a/spec/javascripts/groups/components/item_actions_spec.js b/spec/javascripts/groups/components/item_actions_spec.js
new file mode 100644
index 00000000000..2ce1a749a96
--- /dev/null
+++ b/spec/javascripts/groups/components/item_actions_spec.js
@@ -0,0 +1,110 @@
+import Vue from 'vue';
+
+import itemActionsComponent from '~/groups/components/item_actions.vue';
+import eventHub from '~/groups/event_hub';
+import { mockParentGroupItem, mockChildren } from '../mock_data';
+
+import mountComponent from '../../helpers/vue_mount_component_helper';
+
+const createComponent = (group = mockParentGroupItem, parentGroup = mockChildren[0]) => {
+  const Component = Vue.extend(itemActionsComponent);
+
+  return mountComponent(Component, {
+    group,
+    parentGroup,
+  });
+};
+
+describe('ItemActionsComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('leaveConfirmationMessage', () => {
+      it('should return appropriate string for leave group confirmation', () => {
+        expect(vm.leaveConfirmationMessage).toBe('Are you sure you want to leave the "platform / hardware" group?');
+      });
+    });
+  });
+
+  describe('methods', () => {
+    describe('onLeaveGroup', () => {
+      it('should change `dialogStatus` prop to `true` which shows confirmation dialog', () => {
+        expect(vm.dialogStatus).toBeFalsy();
+        vm.onLeaveGroup();
+        expect(vm.dialogStatus).toBeTruthy();
+      });
+    });
+
+    describe('leaveGroup', () => {
+      it('should change `dialogStatus` prop to `false` and emit `leaveGroup` event with required params when called with `leaveConfirmed` as `true`', () => {
+        spyOn(eventHub, '$emit');
+        vm.dialogStatus = true;
+        vm.leaveGroup(true);
+        expect(vm.dialogStatus).toBeFalsy();
+        expect(eventHub.$emit).toHaveBeenCalledWith('leaveGroup', vm.group, vm.parentGroup);
+      });
+
+      it('should change `dialogStatus` prop to `false` and should NOT emit `leaveGroup` event when called with `leaveConfirmed` as `false`', () => {
+        spyOn(eventHub, '$emit');
+        vm.dialogStatus = true;
+        vm.leaveGroup(false);
+        expect(vm.dialogStatus).toBeFalsy();
+        expect(eventHub.$emit).not.toHaveBeenCalled();
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('should render component template correctly', () => {
+      expect(vm.$el.classList.contains('controls')).toBeTruthy();
+    });
+
+    it('should render Edit Group button with correct attribute values', () => {
+      const group = Object.assign({}, mockParentGroupItem);
+      group.canEdit = true;
+      const newVm = createComponent(group);
+
+      const editBtn = newVm.$el.querySelector('a.edit-group');
+      expect(editBtn).toBeDefined();
+      expect(editBtn.classList.contains('no-expand')).toBeTruthy();
+      expect(editBtn.getAttribute('href')).toBe(group.editPath);
+      expect(editBtn.getAttribute('aria-label')).toBe('Edit group');
+      expect(editBtn.dataset.originalTitle).toBe('Edit group');
+      expect(editBtn.querySelector('i.fa.fa-cogs')).toBeDefined();
+
+      newVm.$destroy();
+    });
+
+    it('should render Leave Group button with correct attribute values', () => {
+      const group = Object.assign({}, mockParentGroupItem);
+      group.canLeave = true;
+      const newVm = createComponent(group);
+
+      const leaveBtn = newVm.$el.querySelector('a.leave-group');
+      expect(leaveBtn).toBeDefined();
+      expect(leaveBtn.classList.contains('no-expand')).toBeTruthy();
+      expect(leaveBtn.getAttribute('href')).toBe(group.leavePath);
+      expect(leaveBtn.getAttribute('aria-label')).toBe('Leave this group');
+      expect(leaveBtn.dataset.originalTitle).toBe('Leave this group');
+      expect(leaveBtn.querySelector('i.fa.fa-sign-out')).toBeDefined();
+
+      newVm.$destroy();
+    });
+
+    it('should show modal dialog when `dialogStatus` is set to `true`', () => {
+      vm.dialogStatus = true;
+      const modalDialogEl = vm.$el.querySelector('.modal.popup-dialog');
+      expect(modalDialogEl).toBeDefined();
+      expect(modalDialogEl.querySelector('.modal-title').innerText.trim()).toBe('Are you sure?');
+      expect(modalDialogEl.querySelector('.btn.btn-warning').innerText.trim()).toBe('Leave');
+    });
+  });
+});
diff --git a/spec/javascripts/groups/components/item_caret_spec.js b/spec/javascripts/groups/components/item_caret_spec.js
new file mode 100644
index 00000000000..4310a07e6e6
--- /dev/null
+++ b/spec/javascripts/groups/components/item_caret_spec.js
@@ -0,0 +1,40 @@
+import Vue from 'vue';
+
+import itemCaretComponent from '~/groups/components/item_caret.vue';
+
+import mountComponent from '../../helpers/vue_mount_component_helper';
+
+const createComponent = (isGroupOpen = false) => {
+  const Component = Vue.extend(itemCaretComponent);
+
+  return mountComponent(Component, {
+    isGroupOpen,
+  });
+};
+
+describe('ItemCaretComponent', () => {
+  describe('template', () => {
+    it('should render component template correctly', () => {
+      const vm = createComponent();
+      vm.$mount();
+      expect(vm.$el.classList.contains('folder-caret')).toBeTruthy();
+      vm.$destroy();
+    });
+
+    it('should render caret down icon if `isGroupOpen` prop is `true`', () => {
+      const vm = createComponent(true);
+      vm.$mount();
+      expect(vm.$el.querySelectorAll('i.fa.fa-caret-down').length).toBe(1);
+      expect(vm.$el.querySelectorAll('i.fa.fa-caret-right').length).toBe(0);
+      vm.$destroy();
+    });
+
+    it('should render caret right icon if `isGroupOpen` prop is `false`', () => {
+      const vm = createComponent();
+      vm.$mount();
+      expect(vm.$el.querySelectorAll('i.fa.fa-caret-down').length).toBe(0);
+      expect(vm.$el.querySelectorAll('i.fa.fa-caret-right').length).toBe(1);
+      vm.$destroy();
+    });
+  });
+});
diff --git a/spec/javascripts/groups/components/item_stats_spec.js b/spec/javascripts/groups/components/item_stats_spec.js
new file mode 100644
index 00000000000..e200f9f08bd
--- /dev/null
+++ b/spec/javascripts/groups/components/item_stats_spec.js
@@ -0,0 +1,159 @@
+import Vue from 'vue';
+
+import itemStatsComponent from '~/groups/components/item_stats.vue';
+import {
+  mockParentGroupItem,
+  ITEM_TYPE,
+  VISIBILITY_TYPE_ICON,
+  GROUP_VISIBILITY_TYPE,
+  PROJECT_VISIBILITY_TYPE,
+} from '../mock_data';
+
+import mountComponent from '../../helpers/vue_mount_component_helper';
+
+const createComponent = (item = mockParentGroupItem) => {
+  const Component = Vue.extend(itemStatsComponent);
+
+  return mountComponent(Component, {
+    item,
+  });
+};
+
+describe('ItemStatsComponent', () => {
+  describe('computed', () => {
+    describe('visibilityIcon', () => {
+      it('should return icon class based on `item.visibility` value', () => {
+        Object.keys(VISIBILITY_TYPE_ICON).forEach((visibility) => {
+          const item = Object.assign({}, mockParentGroupItem, { visibility });
+          const vm = createComponent(item);
+          vm.$mount();
+          expect(vm.visibilityIcon).toBe(VISIBILITY_TYPE_ICON[visibility]);
+          vm.$destroy();
+        });
+      });
+    });
+
+    describe('visibilityTooltip', () => {
+      it('should return tooltip string for Group based on `item.visibility` value', () => {
+        Object.keys(GROUP_VISIBILITY_TYPE).forEach((visibility) => {
+          const item = Object.assign({}, mockParentGroupItem, {
+            visibility,
+            type: ITEM_TYPE.GROUP,
+          });
+          const vm = createComponent(item);
+          vm.$mount();
+          expect(vm.visibilityTooltip).toBe(GROUP_VISIBILITY_TYPE[visibility]);
+          vm.$destroy();
+        });
+      });
+
+      it('should return tooltip string for Project based on `item.visibility` value', () => {
+        Object.keys(PROJECT_VISIBILITY_TYPE).forEach((visibility) => {
+          const item = Object.assign({}, mockParentGroupItem, {
+            visibility,
+            type: ITEM_TYPE.PROJECT,
+          });
+          const vm = createComponent(item);
+          vm.$mount();
+          expect(vm.visibilityTooltip).toBe(PROJECT_VISIBILITY_TYPE[visibility]);
+          vm.$destroy();
+        });
+      });
+    });
+
+    describe('isProject', () => {
+      it('should return boolean value representing whether `item.type` is Project or not', () => {
+        let item;
+        let vm;
+
+        item = Object.assign({}, mockParentGroupItem, { type: ITEM_TYPE.PROJECT });
+        vm = createComponent(item);
+        vm.$mount();
+        expect(vm.isProject).toBeTruthy();
+        vm.$destroy();
+
+        item = Object.assign({}, mockParentGroupItem, { type: ITEM_TYPE.GROUP });
+        vm = createComponent(item);
+        vm.$mount();
+        expect(vm.isProject).toBeFalsy();
+        vm.$destroy();
+      });
+    });
+
+    describe('isGroup', () => {
+      it('should return boolean value representing whether `item.type` is Group or not', () => {
+        let item;
+        let vm;
+
+        item = Object.assign({}, mockParentGroupItem, { type: ITEM_TYPE.GROUP });
+        vm = createComponent(item);
+        vm.$mount();
+        expect(vm.isGroup).toBeTruthy();
+        vm.$destroy();
+
+        item = Object.assign({}, mockParentGroupItem, { type: ITEM_TYPE.PROJECT });
+        vm = createComponent(item);
+        vm.$mount();
+        expect(vm.isGroup).toBeFalsy();
+        vm.$destroy();
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('should render component template correctly', () => {
+      const vm = createComponent();
+      vm.$mount();
+
+      const visibilityIconEl = vm.$el.querySelector('.item-visibility');
+      expect(vm.$el.classList.contains('.stats')).toBeDefined();
+      expect(visibilityIconEl).toBeDefined();
+      expect(visibilityIconEl.dataset.originalTitle).toBe(vm.visibilityTooltip);
+      expect(visibilityIconEl.querySelector('i.fa')).toBeDefined();
+
+      vm.$destroy();
+    });
+
+    it('should render stat icons if `item.type` is Group', () => {
+      const item = Object.assign({}, mockParentGroupItem, { type: ITEM_TYPE.GROUP });
+      const vm = createComponent(item);
+      vm.$mount();
+
+      const subgroupIconEl = vm.$el.querySelector('span.number-subgroups');
+      expect(subgroupIconEl).toBeDefined();
+      expect(subgroupIconEl.dataset.originalTitle).toBe('Subgroups');
+      expect(subgroupIconEl.querySelector('i.fa.fa-folder')).toBeDefined();
+      expect(subgroupIconEl.innerText.trim()).toBe(`${vm.item.subgroupCount}`);
+
+      const projectsIconEl = vm.$el.querySelector('span.number-projects');
+      expect(projectsIconEl).toBeDefined();
+      expect(projectsIconEl.dataset.originalTitle).toBe('Projects');
+      expect(projectsIconEl.querySelector('i.fa.fa-bookmark')).toBeDefined();
+      expect(projectsIconEl.innerText.trim()).toBe(`${vm.item.projectCount}`);
+
+      const membersIconEl = vm.$el.querySelector('span.number-users');
+      expect(membersIconEl).toBeDefined();
+      expect(membersIconEl.dataset.originalTitle).toBe('Members');
+      expect(membersIconEl.querySelector('i.fa.fa-users')).toBeDefined();
+      expect(membersIconEl.innerText.trim()).toBe(`${vm.item.memberCount}`);
+
+      vm.$destroy();
+    });
+
+    it('should render stat icons if `item.type` is Project', () => {
+      const item = Object.assign({}, mockParentGroupItem, {
+        type: ITEM_TYPE.PROJECT,
+        starCount: 4,
+      });
+      const vm = createComponent(item);
+      vm.$mount();
+
+      const projectStarIconEl = vm.$el.querySelector('.project-stars');
+      expect(projectStarIconEl).toBeDefined();
+      expect(projectStarIconEl.querySelector('i.fa.fa-star')).toBeDefined();
+      expect(projectStarIconEl.innerText.trim()).toBe(`${vm.item.starCount}`);
+
+      vm.$destroy();
+    });
+  });
+});
diff --git a/spec/javascripts/groups/components/item_type_icon_spec.js b/spec/javascripts/groups/components/item_type_icon_spec.js
new file mode 100644
index 00000000000..528e6ed1b4c
--- /dev/null
+++ b/spec/javascripts/groups/components/item_type_icon_spec.js
@@ -0,0 +1,54 @@
+import Vue from 'vue';
+
+import itemTypeIconComponent from '~/groups/components/item_type_icon.vue';
+import { ITEM_TYPE } from '../mock_data';
+
+import mountComponent from '../../helpers/vue_mount_component_helper';
+
+const createComponent = (itemType = ITEM_TYPE.GROUP, isGroupOpen = false) => {
+  const Component = Vue.extend(itemTypeIconComponent);
+
+  return mountComponent(Component, {
+    itemType,
+    isGroupOpen,
+  });
+};
+
+describe('ItemTypeIconComponent', () => {
+  describe('template', () => {
+    it('should render component template correctly', () => {
+      const vm = createComponent();
+      vm.$mount();
+      expect(vm.$el.classList.contains('item-type-icon')).toBeTruthy();
+      vm.$destroy();
+    });
+
+    it('should render folder open or close icon based `isGroupOpen` prop value', () => {
+      let vm;
+
+      vm = createComponent(ITEM_TYPE.GROUP, true);
+      vm.$mount();
+      expect(vm.$el.querySelector('i.fa.fa-folder-open')).toBeDefined();
+      vm.$destroy();
+
+      vm = createComponent(ITEM_TYPE.GROUP);
+      vm.$mount();
+      expect(vm.$el.querySelector('i.fa.fa-folder')).toBeDefined();
+      vm.$destroy();
+    });
+
+    it('should render bookmark icon based on `isProject` prop value', () => {
+      let vm;
+
+      vm = createComponent(ITEM_TYPE.PROJECT);
+      vm.$mount();
+      expect(vm.$el.querySelectorAll('i.fa.fa-bookmark').length).toBe(1);
+      vm.$destroy();
+
+      vm = createComponent(ITEM_TYPE.GROUP);
+      vm.$mount();
+      expect(vm.$el.querySelectorAll('i.fa.fa-bookmark').length).toBe(0);
+      vm.$destroy();
+    });
+  });
+});
diff --git a/spec/javascripts/groups/group_item_spec.js b/spec/javascripts/groups/group_item_spec.js
deleted file mode 100644
index 25e10552d95..00000000000
--- a/spec/javascripts/groups/group_item_spec.js
+++ /dev/null
@@ -1,102 +0,0 @@
-import Vue from 'vue';
-import groupItemComponent from '~/groups/components/group_item.vue';
-import GroupsStore from '~/groups/stores/groups_store';
-import { group1 } from './mock_data';
-
-describe('Groups Component', () => {
-  let GroupItemComponent;
-  let component;
-  let store;
-  let group;
-
-  describe('group with default data', () => {
-    beforeEach((done) => {
-      GroupItemComponent = Vue.extend(groupItemComponent);
-      store = new GroupsStore();
-      group = store.decorateGroup(group1);
-
-      component = new GroupItemComponent({
-        propsData: {
-          group,
-        },
-      }).$mount();
-
-      Vue.nextTick(() => {
-        done();
-      });
-    });
-
-    afterEach(() => {
-      component.$destroy();
-    });
-
-    it('should render the group item correctly', () => {
-      expect(component.$el.classList.contains('group-row')).toBe(true);
-      expect(component.$el.classList.contains('.no-description')).toBe(false);
-      expect(component.$el.querySelector('.number-projects').textContent).toContain(group.numberProjects);
-      expect(component.$el.querySelector('.number-users').textContent).toContain(group.numberUsers);
-      expect(component.$el.querySelector('.group-visibility')).toBeDefined();
-      expect(component.$el.querySelector('.avatar-container')).toBeDefined();
-      expect(component.$el.querySelector('.title').textContent).toContain(group.name);
-      expect(component.$el.querySelector('.access-type').textContent).toContain(group.permissions.humanGroupAccess);
-      expect(component.$el.querySelector('.description').textContent).toContain(group.description);
-      expect(component.$el.querySelector('.edit-group')).toBeDefined();
-      expect(component.$el.querySelector('.leave-group')).toBeDefined();
-    });
-  });
-
-  describe('group without description', () => {
-    beforeEach((done) => {
-      GroupItemComponent = Vue.extend(groupItemComponent);
-      store = new GroupsStore();
-      group1.description = '';
-      group = store.decorateGroup(group1);
-
-      component = new GroupItemComponent({
-        propsData: {
-          group,
-        },
-      }).$mount();
-
-      Vue.nextTick(() => {
-        done();
-      });
-    });
-
-    afterEach(() => {
-      component.$destroy();
-    });
-
-    it('should render group item correctly', () => {
-      expect(component.$el.querySelector('.description').textContent).toBe('');
-      expect(component.$el.classList.contains('.no-description')).toBe(false);
-    });
-  });
-
-  describe('user has not access to group', () => {
-    beforeEach((done) => {
-      GroupItemComponent = Vue.extend(groupItemComponent);
-      store = new GroupsStore();
-      group1.permissions.human_group_access = null;
-      group = store.decorateGroup(group1);
-
-      component = new GroupItemComponent({
-        propsData: {
-          group,
-        },
-      }).$mount();
-
-      Vue.nextTick(() => {
-        done();
-      });
-    });
-
-    afterEach(() => {
-      component.$destroy();
-    });
-
-    it('should not display access type', () => {
-      expect(component.$el.querySelector('.access-type')).toBeNull();
-    });
-  });
-});
diff --git a/spec/javascripts/groups/groups_spec.js b/spec/javascripts/groups/groups_spec.js
deleted file mode 100644
index b14153dbbfa..00000000000
--- a/spec/javascripts/groups/groups_spec.js
+++ /dev/null
@@ -1,99 +0,0 @@
-import Vue from 'vue';
-import eventHub from '~/groups/event_hub';
-import groupFolderComponent from '~/groups/components/group_folder.vue';
-import groupItemComponent from '~/groups/components/group_item.vue';
-import groupsComponent from '~/groups/components/groups.vue';
-import GroupsStore from '~/groups/stores/groups_store';
-import { groupsData } from './mock_data';
-
-describe('Groups Component', () => {
-  let GroupsComponent;
-  let store;
-  let component;
-  let groups;
-
-  beforeEach((done) => {
-    Vue.component('group-folder', groupFolderComponent);
-    Vue.component('group-item', groupItemComponent);
-
-    store = new GroupsStore();
-    groups = store.setGroups(groupsData.groups);
-
-    store.storePagination(groupsData.pagination);
-
-    GroupsComponent = Vue.extend(groupsComponent);
-
-    component = new GroupsComponent({
-      propsData: {
-        groups: store.state.groups,
-        pageInfo: store.state.pageInfo,
-      },
-    }).$mount();
-
-    Vue.nextTick(() => {
-      done();
-    });
-  });
-
-  afterEach(() => {
-    component.$destroy();
-  });
-
-  describe('with data', () => {
-    it('should render a list of groups', () => {
-      expect(component.$el.classList.contains('groups-list-tree-container')).toBe(true);
-      expect(component.$el.querySelector('#group-12')).toBeDefined();
-      expect(component.$el.querySelector('#group-1119')).toBeDefined();
-      expect(component.$el.querySelector('#group-1120')).toBeDefined();
-    });
-
-    it('should respect the order of groups', () => {
-      const wrap = component.$el.querySelector('.groups-list-tree-container > .group-list-tree');
-      expect(wrap.querySelector('.group-row:nth-child(1)').id).toBe('group-12');
-      expect(wrap.querySelector('.group-row:nth-child(2)').id).toBe('group-1119');
-    });
-
-    it('should render group and its subgroup', () => {
-      const lists = component.$el.querySelectorAll('.group-list-tree');
-
-      expect(lists.length).toBe(3); // one parent and two subgroups
-
-      expect(lists[0].querySelector('#group-1119').classList.contains('is-open')).toBe(true);
-      expect(lists[0].querySelector('#group-1119').classList.contains('has-subgroups')).toBe(true);
-
-      expect(lists[2].querySelector('#group-1120').textContent).toContain(groups.id1119.subGroups.id1120.name);
-    });
-
-    it('should render group identicon when group avatar is not present', () => {
-      const avatar = component.$el.querySelector('#group-12 .avatar-container .avatar');
-      expect(avatar.nodeName).toBe('DIV');
-      expect(avatar.classList.contains('identicon')).toBeTruthy();
-      expect(avatar.getAttribute('style').indexOf('background-color') > -1).toBeTruthy();
-    });
-
-    it('should render group avatar when group avatar is present', () => {
-      const avatar = component.$el.querySelector('#group-1120 .avatar-container .avatar');
-      expect(avatar.nodeName).toBe('IMG');
-      expect(avatar.classList.contains('identicon')).toBeFalsy();
-    });
-
-    it('should remove prefix of parent group', () => {
-      expect(component.$el.querySelector('#group-12 #group-1128 .title').textContent).toContain('level2 / level3 / level4');
-    });
-
-    it('should remove the group after leaving the group', (done) => {
-      spyOn(window, 'confirm').and.returnValue(true);
-
-      eventHub.$on('leaveGroup', (group, collection) => {
-        store.removeGroup(group, collection);
-      });
-
-      component.$el.querySelector('#group-12 .leave-group').click();
-
-      Vue.nextTick(() => {
-        expect(component.$el.querySelector('#group-12')).toBeNull();
-        done();
-      });
-    });
-  });
-});
diff --git a/spec/javascripts/groups/mock_data.js b/spec/javascripts/groups/mock_data.js
index 5bb84b591f4..6184d671790 100644
--- a/spec/javascripts/groups/mock_data.js
+++ b/spec/javascripts/groups/mock_data.js
@@ -1,114 +1,380 @@
-const group1 = {
-  id: 12,
-  name: 'level1',
-  path: 'level1',
-  description: 'foo',
-  visibility: 'public',
-  avatar_url: null,
-  web_url: 'http://localhost:3000/groups/level1',
-  group_path: '/level1',
-  full_name: 'level1',
-  full_path: 'level1',
-  parent_id: null,
-  created_at: '2017-05-15T19:01:23.670Z',
-  updated_at: '2017-05-15T19:01:23.670Z',
-  number_projects_with_delimiter: '1',
-  number_users_with_delimiter: '1',
-  has_subgroups: true,
-  permissions: {
-    human_group_access: 'Master',
-  },
+export const mockEndpoint = '/dashboard/groups.json';
+
+export const ITEM_TYPE = {
+  PROJECT: 'project',
+  GROUP: 'group',
 };
 
-// This group has no direct parent, should be placed as subgroup of group1
-const group14 = {
-  id: 1128,
-  name: 'level4',
-  path: 'level4',
-  description: 'foo',
-  visibility: 'public',
-  avatar_url: null,
-  web_url: 'http://localhost:3000/groups/level1/level2/level3/level4',
-  group_path: '/level1/level2/level3/level4',
-  full_name: 'level1 / level2 / level3 / level4',
-  full_path: 'level1/level2/level3/level4',
-  parent_id: 1127,
-  created_at: '2017-05-15T19:02:01.645Z',
-  updated_at: '2017-05-15T19:02:01.645Z',
-  number_projects_with_delimiter: '1',
-  number_users_with_delimiter: '1',
-  has_subgroups: true,
-  permissions: {
-    human_group_access: 'Master',
-  },
+export const GROUP_VISIBILITY_TYPE = {
+  public: 'Public - The group and any public projects can be viewed without any authentication.',
+  internal: 'Internal - The group and any internal projects can be viewed by any logged in user.',
+  private: 'Private - The group and its projects can only be viewed by members.',
 };
 
-const group2 = {
-  id: 1119,
-  name: 'devops',
-  path: 'devops',
-  description: 'foo',
-  visibility: 'public',
-  avatar_url: null,
-  web_url: 'http://localhost:3000/groups/devops',
-  group_path: '/devops',
-  full_name: 'devops',
-  full_path: 'devops',
-  parent_id: null,
-  created_at: '2017-05-11T19:35:09.635Z',
-  updated_at: '2017-05-11T19:35:09.635Z',
-  number_projects_with_delimiter: '1',
-  number_users_with_delimiter: '1',
-  has_subgroups: true,
-  permissions: {
-    human_group_access: 'Master',
-  },
+export const PROJECT_VISIBILITY_TYPE = {
+  public: 'Public - The project can be accessed without any authentication.',
+  internal: 'Internal - The project can be accessed by any logged in user.',
+  private: 'Private - Project access must be granted explicitly to each user.',
+};
+
+export const VISIBILITY_TYPE_ICON = {
+  public: 'fa-globe',
+  internal: 'fa-shield',
+  private: 'fa-lock',
 };
 
-const group21 = {
-  id: 1120,
-  name: 'chef',
-  path: 'chef',
-  description: 'foo',
+export const mockParentGroupItem = {
+  id: 55,
+  name: 'hardware',
+  description: '',
   visibility: 'public',
-  avatar_url: '/uploads/-/system/group/avatar/2/GitLab.png',
-  web_url: 'http://localhost:3000/groups/devops/chef',
-  group_path: '/devops/chef',
-  full_name: 'devops / chef',
-  full_path: 'devops/chef',
-  parent_id: 1119,
-  created_at: '2017-05-11T19:51:04.060Z',
-  updated_at: '2017-05-11T19:51:04.060Z',
-  number_projects_with_delimiter: '1',
-  number_users_with_delimiter: '1',
-  has_subgroups: true,
-  permissions: {
-    human_group_access: 'Master',
-  },
+  fullName: 'platform / hardware',
+  relativePath: '/platform/hardware',
+  canEdit: true,
+  type: 'group',
+  avatarUrl: null,
+  permission: 'Owner',
+  editPath: '/groups/platform/hardware/edit',
+  childrenCount: 3,
+  leavePath: '/groups/platform/hardware/group_members/leave',
+  parentId: 54,
+  memberCount: '1',
+  projectCount: 1,
+  subgroupCount: 2,
+  canLeave: false,
+  children: [],
+  isOpen: true,
+  isChildrenLoading: false,
+  isBeingRemoved: false,
 };
 
-const groupsData = {
-  groups: [group1, group14, group2, group21],
-  pagination: {
-    Date: 'Mon, 22 May 2017 22:31:52 GMT',
-    'X-Prev-Page': '1',
-    'X-Content-Type-Options': 'nosniff',
-    'X-Total': '31',
-    'Transfer-Encoding': 'chunked',
-    'X-Runtime': '0.611144',
-    'X-Xss-Protection': '1; mode=block',
-    'X-Request-Id': 'f5db8368-3ce5-4aa4-89d2-a125d9dead09',
-    'X-Ua-Compatible': 'IE=edge',
-    'X-Per-Page': '20',
-    Link: '<http://localhost:3000/dashboard/groups.json?page=1&per_page=20>; rel="prev", <http://localhost:3000/dashboard/groups.json?page=1&per_page=20>; rel="first", <http://localhost:3000/dashboard/groups.json?page=2&per_page=20>; rel="last"',
-    'X-Next-Page': '',
-    Etag: 'W/"a82f846947136271cdb7d55d19ef33d2"',
-    'X-Frame-Options': 'DENY',
-    'Content-Type': 'application/json; charset=utf-8',
-    'Cache-Control': 'max-age=0, private, must-revalidate',
-    'X-Total-Pages': '2',
-    'X-Page': '2',
+export const mockRawChildren = [
+  {
+    id: 57,
+    name: 'bsp',
+    description: '',
+    visibility: 'public',
+    full_name: 'platform / hardware / bsp',
+    relative_path: '/platform/hardware/bsp',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/platform/hardware/bsp/edit',
+    children_count: 6,
+    leave_path: '/groups/platform/hardware/bsp/group_members/leave',
+    parent_id: 55,
+    number_users_with_delimiter: '1',
+    project_count: 4,
+    subgroup_count: 2,
+    can_leave: false,
+    children: [],
+  },
+];
+
+export const mockChildren = [
+  {
+    id: 57,
+    name: 'bsp',
+    description: '',
+    visibility: 'public',
+    fullName: 'platform / hardware / bsp',
+    relativePath: '/platform/hardware/bsp',
+    canEdit: true,
+    type: 'group',
+    avatarUrl: null,
+    permission: 'Owner',
+    editPath: '/groups/platform/hardware/bsp/edit',
+    childrenCount: 6,
+    leavePath: '/groups/platform/hardware/bsp/group_members/leave',
+    parentId: 55,
+    memberCount: '1',
+    projectCount: 4,
+    subgroupCount: 2,
+    canLeave: false,
+    children: [],
+    isOpen: true,
+    isChildrenLoading: false,
+    isBeingRemoved: false,
   },
+];
+
+export const mockGroups = [
+  {
+    id: 75,
+    name: 'test-group',
+    description: '',
+    visibility: 'public',
+    full_name: 'test-group',
+    relative_path: '/test-group',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/test-group/edit',
+    children_count: 2,
+    leave_path: '/groups/test-group/group_members/leave',
+    parent_id: null,
+    number_users_with_delimiter: '1',
+    project_count: 2,
+    subgroup_count: 0,
+    can_leave: false,
+  },
+  {
+    id: 67,
+    name: 'open-source',
+    description: '',
+    visibility: 'private',
+    full_name: 'open-source',
+    relative_path: '/open-source',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/open-source/edit',
+    children_count: 0,
+    leave_path: '/groups/open-source/group_members/leave',
+    parent_id: null,
+    number_users_with_delimiter: '1',
+    project_count: 0,
+    subgroup_count: 0,
+    can_leave: false,
+  },
+  {
+    id: 54,
+    name: 'platform',
+    description: '',
+    visibility: 'public',
+    full_name: 'platform',
+    relative_path: '/platform',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/platform/edit',
+    children_count: 1,
+    leave_path: '/groups/platform/group_members/leave',
+    parent_id: null,
+    number_users_with_delimiter: '1',
+    project_count: 0,
+    subgroup_count: 1,
+    can_leave: false,
+  },
+  {
+    id: 5,
+    name: 'H5bp',
+    description: 'Minus dolor consequuntur qui nam recusandae quam incidunt.',
+    visibility: 'public',
+    full_name: 'H5bp',
+    relative_path: '/h5bp',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/h5bp/edit',
+    children_count: 1,
+    leave_path: '/groups/h5bp/group_members/leave',
+    parent_id: null,
+    number_users_with_delimiter: '5',
+    project_count: 1,
+    subgroup_count: 0,
+    can_leave: false,
+  },
+  {
+    id: 4,
+    name: 'Twitter',
+    description: 'Deserunt hic nostrum placeat veniam.',
+    visibility: 'public',
+    full_name: 'Twitter',
+    relative_path: '/twitter',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/twitter/edit',
+    children_count: 2,
+    leave_path: '/groups/twitter/group_members/leave',
+    parent_id: null,
+    number_users_with_delimiter: '5',
+    project_count: 2,
+    subgroup_count: 0,
+    can_leave: false,
+  },
+  {
+    id: 3,
+    name: 'Documentcloud',
+    description: 'Consequatur saepe totam ea pariatur maxime.',
+    visibility: 'public',
+    full_name: 'Documentcloud',
+    relative_path: '/documentcloud',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/documentcloud/edit',
+    children_count: 1,
+    leave_path: '/groups/documentcloud/group_members/leave',
+    parent_id: null,
+    number_users_with_delimiter: '5',
+    project_count: 1,
+    subgroup_count: 0,
+    can_leave: false,
+  },
+  {
+    id: 2,
+    name: 'Gitlab Org',
+    description: 'Debitis ea quas aperiam velit doloremque ab.',
+    visibility: 'public',
+    full_name: 'Gitlab Org',
+    relative_path: '/gitlab-org',
+    can_edit: true,
+    type: 'group',
+    avatar_url: '/uploads/-/system/group/avatar/2/GitLab.png',
+    permission: 'Owner',
+    edit_path: '/groups/gitlab-org/edit',
+    children_count: 4,
+    leave_path: '/groups/gitlab-org/group_members/leave',
+    parent_id: null,
+    number_users_with_delimiter: '5',
+    project_count: 4,
+    subgroup_count: 0,
+    can_leave: false,
+  },
+];
+
+export const mockSearchedGroups = [
+  {
+    id: 55,
+    name: 'hardware',
+    description: '',
+    visibility: 'public',
+    full_name: 'platform / hardware',
+    relative_path: '/platform/hardware',
+    can_edit: true,
+    type: 'group',
+    avatar_url: null,
+    permission: 'Owner',
+    edit_path: '/groups/platform/hardware/edit',
+    children_count: 3,
+    leave_path: '/groups/platform/hardware/group_members/leave',
+    parent_id: 54,
+    number_users_with_delimiter: '1',
+    project_count: 1,
+    subgroup_count: 2,
+    can_leave: false,
+    children: [
+      {
+        id: 57,
+        name: 'bsp',
+        description: '',
+        visibility: 'public',
+        full_name: 'platform / hardware / bsp',
+        relative_path: '/platform/hardware/bsp',
+        can_edit: true,
+        type: 'group',
+        avatar_url: null,
+        permission: 'Owner',
+        edit_path: '/groups/platform/hardware/bsp/edit',
+        children_count: 6,
+        leave_path: '/groups/platform/hardware/bsp/group_members/leave',
+        parent_id: 55,
+        number_users_with_delimiter: '1',
+        project_count: 4,
+        subgroup_count: 2,
+        can_leave: false,
+        children: [
+          {
+            id: 60,
+            name: 'kernel',
+            description: '',
+            visibility: 'public',
+            full_name: 'platform / hardware / bsp / kernel',
+            relative_path: '/platform/hardware/bsp/kernel',
+            can_edit: true,
+            type: 'group',
+            avatar_url: null,
+            permission: 'Owner',
+            edit_path: '/groups/platform/hardware/bsp/kernel/edit',
+            children_count: 1,
+            leave_path: '/groups/platform/hardware/bsp/kernel/group_members/leave',
+            parent_id: 57,
+            number_users_with_delimiter: '1',
+            project_count: 0,
+            subgroup_count: 1,
+            can_leave: false,
+            children: [
+              {
+                id: 61,
+                name: 'common',
+                description: '',
+                visibility: 'public',
+                full_name: 'platform / hardware / bsp / kernel / common',
+                relative_path: '/platform/hardware/bsp/kernel/common',
+                can_edit: true,
+                type: 'group',
+                avatar_url: null,
+                permission: 'Owner',
+                edit_path: '/groups/platform/hardware/bsp/kernel/common/edit',
+                children_count: 2,
+                leave_path: '/groups/platform/hardware/bsp/kernel/common/group_members/leave',
+                parent_id: 60,
+                number_users_with_delimiter: '1',
+                project_count: 2,
+                subgroup_count: 0,
+                can_leave: false,
+                children: [
+                  {
+                    id: 17,
+                    name: 'v4.4',
+                    description: 'Voluptatem qui ea error aperiam veritatis doloremque consequatur temporibus.',
+                    visibility: 'public',
+                    full_name: 'platform / hardware / bsp / kernel / common / v4.4',
+                    relative_path: '/platform/hardware/bsp/kernel/common/v4.4',
+                    can_edit: true,
+                    type: 'project',
+                    avatar_url: null,
+                    permission: null,
+                    edit_path: '/platform/hardware/bsp/kernel/common/v4.4/edit',
+                    star_count: 0,
+                  },
+                  {
+                    id: 16,
+                    name: 'v4.1',
+                    description: 'Rerum expedita voluptatem doloribus neque ducimus ut hic.',
+                    visibility: 'public',
+                    full_name: 'platform / hardware / bsp / kernel / common / v4.1',
+                    relative_path: '/platform/hardware/bsp/kernel/common/v4.1',
+                    can_edit: true,
+                    type: 'project',
+                    avatar_url: null,
+                    permission: null,
+                    edit_path: '/platform/hardware/bsp/kernel/common/v4.1/edit',
+                    star_count: 0,
+                  },
+                ],
+              },
+            ],
+          },
+        ],
+      },
+    ],
+  },
+];
+
+export const mockRawPageInfo = {
+  'x-per-page': 10,
+  'x-page': 10,
+  'x-total': 10,
+  'x-total-pages': 10,
+  'x-next-page': 10,
+  'x-prev-page': 10,
 };
 
-export { groupsData, group1 };
+export const mockPageInfo = {
+  perPage: 10,
+  page: 10,
+  total: 10,
+  totalPages: 10,
+  nextPage: 10,
+  prevPage: 10,
+};
diff --git a/spec/javascripts/groups/service/groups_service_spec.js b/spec/javascripts/groups/service/groups_service_spec.js
new file mode 100644
index 00000000000..20bb63687f7
--- /dev/null
+++ b/spec/javascripts/groups/service/groups_service_spec.js
@@ -0,0 +1,42 @@
+import Vue from 'vue';
+import VueResource from 'vue-resource';
+
+import GroupsService from '~/groups/service/groups_service';
+import { mockEndpoint, mockParentGroupItem } from '../mock_data';
+
+Vue.use(VueResource);
+
+describe('GroupsService', () => {
+  let service;
+
+  beforeEach(() => {
+    service = new GroupsService(mockEndpoint);
+  });
+
+  describe('getGroups', () => {
+    it('should return promise for `GET` request on provided endpoint', () => {
+      spyOn(service.groups, 'get').and.stub();
+      const queryParams = {
+        page: 2,
+        filter: 'git',
+        sort: 'created_asc',
+        archived: true,
+      };
+
+      service.getGroups(55, 2, 'git', 'created_asc', true);
+      expect(service.groups.get).toHaveBeenCalledWith({ parent_id: 55 });
+
+      service.getGroups(null, 2, 'git', 'created_asc', true);
+      expect(service.groups.get).toHaveBeenCalledWith(queryParams);
+    });
+  });
+
+  describe('leaveGroup', () => {
+    it('should return promise for `DELETE` request on provided endpoint', () => {
+      spyOn(Vue.http, 'delete').and.stub();
+
+      service.leaveGroup(mockParentGroupItem.leavePath);
+      expect(Vue.http.delete).toHaveBeenCalledWith(mockParentGroupItem.leavePath);
+    });
+  });
+});
diff --git a/spec/javascripts/groups/store/groups_store_spec.js b/spec/javascripts/groups/store/groups_store_spec.js
new file mode 100644
index 00000000000..d74f38f476e
--- /dev/null
+++ b/spec/javascripts/groups/store/groups_store_spec.js
@@ -0,0 +1,110 @@
+import GroupsStore from '~/groups/store/groups_store';
+import {
+  mockGroups, mockSearchedGroups,
+  mockParentGroupItem, mockRawChildren,
+  mockRawPageInfo,
+} from '../mock_data';
+
+describe('ProjectsStore', () => {
+  describe('constructor', () => {
+    it('should initialize default state', () => {
+      let store;
+
+      store = new GroupsStore();
+      expect(Object.keys(store.state).length).toBe(2);
+      expect(Array.isArray(store.state.groups)).toBeTruthy();
+      expect(Object.keys(store.state.pageInfo).length).toBe(0);
+      expect(store.hideProjects).not.toBeDefined();
+
+      store = new GroupsStore(true);
+      expect(store.hideProjects).toBeTruthy();
+    });
+  });
+
+  describe('setGroups', () => {
+    it('should set groups to state', () => {
+      const store = new GroupsStore();
+      spyOn(store, 'formatGroupItem').and.callThrough();
+
+      store.setGroups(mockGroups);
+      expect(store.state.groups.length).toBe(mockGroups.length);
+      expect(store.formatGroupItem).toHaveBeenCalledWith(jasmine.any(Object));
+      expect(Object.keys(store.state.groups[0]).indexOf('fullName') > -1).toBeTruthy();
+    });
+  });
+
+  describe('setSearchedGroups', () => {
+    it('should set searched groups to state', () => {
+      const store = new GroupsStore();
+      spyOn(store, 'formatGroupItem').and.callThrough();
+
+      store.setSearchedGroups(mockSearchedGroups);
+      expect(store.state.groups.length).toBe(mockSearchedGroups.length);
+      expect(store.formatGroupItem).toHaveBeenCalledWith(jasmine.any(Object));
+      expect(Object.keys(store.state.groups[0]).indexOf('fullName') > -1).toBeTruthy();
+      expect(Object.keys(store.state.groups[0].children[0]).indexOf('fullName') > -1).toBeTruthy();
+    });
+  });
+
+  describe('setGroupChildren', () => {
+    it('should set children to group item in state', () => {
+      const store = new GroupsStore();
+      spyOn(store, 'formatGroupItem').and.callThrough();
+
+      store.setGroupChildren(mockParentGroupItem, mockRawChildren);
+      expect(store.formatGroupItem).toHaveBeenCalledWith(jasmine.any(Object));
+      expect(mockParentGroupItem.children.length).toBe(1);
+      expect(Object.keys(mockParentGroupItem.children[0]).indexOf('fullName') > -1).toBeTruthy();
+      expect(mockParentGroupItem.isOpen).toBeTruthy();
+      expect(mockParentGroupItem.isChildrenLoading).toBeFalsy();
+    });
+  });
+
+  describe('setPaginationInfo', () => {
+    it('should parse and set pagination info in state', () => {
+      const store = new GroupsStore();
+
+      store.setPaginationInfo(mockRawPageInfo);
+      expect(store.state.pageInfo.perPage).toBe(10);
+      expect(store.state.pageInfo.page).toBe(10);
+      expect(store.state.pageInfo.total).toBe(10);
+      expect(store.state.pageInfo.totalPages).toBe(10);
+      expect(store.state.pageInfo.nextPage).toBe(10);
+      expect(store.state.pageInfo.previousPage).toBe(10);
+    });
+  });
+
+  describe('formatGroupItem', () => {
+    it('should parse group item object and return updated object', () => {
+      let store;
+      let updatedGroupItem;
+
+      store = new GroupsStore();
+      updatedGroupItem = store.formatGroupItem(mockRawChildren[0]);
+      expect(Object.keys(updatedGroupItem).indexOf('fullName') > -1).toBeTruthy();
+      expect(updatedGroupItem.childrenCount).toBe(mockRawChildren[0].children_count);
+      expect(updatedGroupItem.isChildrenLoading).toBe(false);
+      expect(updatedGroupItem.isBeingRemoved).toBe(false);
+
+      store = new GroupsStore(true);
+      updatedGroupItem = store.formatGroupItem(mockRawChildren[0]);
+      expect(Object.keys(updatedGroupItem).indexOf('fullName') > -1).toBeTruthy();
+      expect(updatedGroupItem.childrenCount).toBe(mockRawChildren[0].subgroup_count);
+    });
+  });
+
+  describe('removeGroup', () => {
+    it('should remove children from group item in state', () => {
+      const store = new GroupsStore();
+      const rawParentGroup = Object.assign({}, mockGroups[0]);
+      const rawChildGroup = Object.assign({}, mockGroups[1]);
+
+      store.setGroups([rawParentGroup]);
+      store.setGroupChildren(store.state.groups[0], [rawChildGroup]);
+      const childItem = store.state.groups[0].children[0];
+
+      store.removeGroup(childItem, store.state.groups[0]);
+      expect(store.state.groups[0].children.length).toBe(0);
+    });
+  });
+});
diff --git a/spec/lib/gitlab/group_hierarchy_spec.rb b/spec/lib/gitlab/group_hierarchy_spec.rb
index 8dc83a6db7f..30686634af4 100644
--- a/spec/lib/gitlab/group_hierarchy_spec.rb
+++ b/spec/lib/gitlab/group_hierarchy_spec.rb
@@ -18,6 +18,12 @@ describe Gitlab::GroupHierarchy, :postgresql do
       expect(relation).to include(parent, child1)
     end
 
+    it 'can find ancestors upto a certain level' do
+      relation = described_class.new(Group.where(id: child2)).base_and_ancestors(upto: child1)
+
+      expect(relation).to contain_exactly(child2)
+    end
+
     it 'uses ancestors_base #initialize argument' do
       relation = described_class.new(Group.where(id: child2.id), Group.none).base_and_ancestors
 
@@ -55,6 +61,28 @@ describe Gitlab::GroupHierarchy, :postgresql do
     end
   end
 
+  describe '#descendants' do
+    it 'includes only the descendants' do
+      relation = described_class.new(Group.where(id: parent)).descendants
+
+      expect(relation).to contain_exactly(child1, child2)
+    end
+  end
+
+  describe '#ancestors' do
+    it 'includes only the ancestors' do
+      relation = described_class.new(Group.where(id: child2)).ancestors
+
+      expect(relation).to contain_exactly(child1, parent)
+    end
+
+    it 'can find ancestors upto a certain level' do
+      relation = described_class.new(Group.where(id: child2)).ancestors(upto: child1)
+
+      expect(relation).to be_empty
+    end
+  end
+
   describe '#all_groups' do
     let(:relation) do
       described_class.new(Group.where(id: child1.id)).all_groups
diff --git a/spec/lib/gitlab/multi_collection_paginator_spec.rb b/spec/lib/gitlab/multi_collection_paginator_spec.rb
new file mode 100644
index 00000000000..68bd4f93159
--- /dev/null
+++ b/spec/lib/gitlab/multi_collection_paginator_spec.rb
@@ -0,0 +1,46 @@
+require 'spec_helper'
+
+describe Gitlab::MultiCollectionPaginator do
+  subject(:paginator) { described_class.new(Project.all.order(:id), Group.all.order(:id), per_page: 3) }
+
+  it 'combines both collections' do
+    project = create(:project)
+    group = create(:group)
+
+    expect(paginator.paginate(1)).to eq([project, group])
+  end
+
+  it 'includes elements second collection if first collection is empty' do
+    group = create(:group)
+
+    expect(paginator.paginate(1)).to eq([group])
+  end
+
+  context 'with a full first page' do
+    let!(:all_groups) { create_list(:group, 4) }
+    let!(:all_projects) { create_list(:project, 4) }
+
+    it 'knows the total count of the collection' do
+      expect(paginator.total_count).to eq(8)
+    end
+
+    it 'fills the first page with elements of the first collection' do
+      expect(paginator.paginate(1)).to eq(all_projects.take(3))
+    end
+
+    it 'fils the second page with a mixture of of the first & second collection' do
+      first_collection_element = all_projects.last
+      second_collection_elements = all_groups.take(2)
+
+      expected_collection = [first_collection_element] + second_collection_elements
+
+      expect(paginator.paginate(2)).to eq(expected_collection)
+    end
+
+    it 'fils the last page with elements from the second collection' do
+      expected_collection = all_groups[-2..-1]
+
+      expect(paginator.paginate(3)).to eq(expected_collection)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/path_regex_spec.rb b/spec/lib/gitlab/path_regex_spec.rb
index 1f1c48ee9b5..f1f188cbfb5 100644
--- a/spec/lib/gitlab/path_regex_spec.rb
+++ b/spec/lib/gitlab/path_regex_spec.rb
@@ -213,7 +213,7 @@ describe Gitlab::PathRegex do
     it 'accepts group routes' do
       expect(subject).to match('activity/')
       expect(subject).to match('group_members/')
-      expect(subject).to match('subgroups/')
+      expect(subject).to match('labels/')
     end
 
     it 'is not case sensitive' do
@@ -246,7 +246,7 @@ describe Gitlab::PathRegex do
         it 'accepts group routes' do
           expect(subject).to match('activity/')
           expect(subject).to match('group_members/')
-          expect(subject).to match('subgroups/')
+          expect(subject).to match('labels/')
         end
       end
 
@@ -268,7 +268,7 @@ describe Gitlab::PathRegex do
         it 'accepts group routes' do
           expect(subject).to match('activity/more/')
           expect(subject).to match('group_members/more/')
-          expect(subject).to match('subgroups/more/')
+          expect(subject).to match('labels/more/')
         end
       end
     end
@@ -292,7 +292,7 @@ describe Gitlab::PathRegex do
         it 'rejects group routes' do
           expect(subject).not_to match('root/activity/')
           expect(subject).not_to match('root/group_members/')
-          expect(subject).not_to match('root/subgroups/')
+          expect(subject).not_to match('root/labels/')
         end
       end
 
@@ -314,7 +314,7 @@ describe Gitlab::PathRegex do
         it 'rejects group routes' do
           expect(subject).not_to match('root/activity/more/')
           expect(subject).not_to match('root/group_members/more/')
-          expect(subject).not_to match('root/subgroups/more/')
+          expect(subject).not_to match('root/labels/more/')
         end
       end
     end
@@ -349,7 +349,7 @@ describe Gitlab::PathRegex do
     it 'accepts group routes' do
       expect(subject).to match('activity/')
       expect(subject).to match('group_members/')
-      expect(subject).to match('subgroups/')
+      expect(subject).to match('labels/')
     end
 
     it 'is not case sensitive' do
@@ -382,7 +382,7 @@ describe Gitlab::PathRegex do
     it 'accepts group routes' do
       expect(subject).to match('root/activity/')
       expect(subject).to match('root/group_members/')
-      expect(subject).to match('root/subgroups/')
+      expect(subject).to match('root/labels/')
     end
 
     it 'is not case sensitive' do
diff --git a/spec/lib/gitlab/sql/union_spec.rb b/spec/lib/gitlab/sql/union_spec.rb
index 8026fba9f0a..fe6422c32b6 100644
--- a/spec/lib/gitlab/sql/union_spec.rb
+++ b/spec/lib/gitlab/sql/union_spec.rb
@@ -29,5 +29,12 @@ describe Gitlab::SQL::Union do
 
       expect(union.to_sql).to include('UNION ALL')
     end
+
+    it 'returns `NULL` if all relations are empty' do
+      empty_relation = User.none
+      union = described_class.new([empty_relation, empty_relation])
+
+      expect(union.to_sql).to eq('NULL')
+    end
   end
 end
diff --git a/spec/lib/gitlab/utils/merge_hash_spec.rb b/spec/lib/gitlab/utils/merge_hash_spec.rb
new file mode 100644
index 00000000000..4fa7bb31301
--- /dev/null
+++ b/spec/lib/gitlab/utils/merge_hash_spec.rb
@@ -0,0 +1,33 @@
+require 'spec_helper'
+describe Gitlab::Utils::MergeHash do
+  describe '.crush' do
+    it 'can flatten a hash to each element' do
+      input = { hello: "world", this: { crushes: ["an entire", "hash"] } }
+      expected_result = [:hello, "world", :this, :crushes, "an entire", "hash"]
+
+      expect(described_class.crush(input)).to eq(expected_result)
+    end
+  end
+
+  describe '.elements' do
+    it 'deep merges an array of elements' do
+      input = [{ hello: ["world"] },
+               { hello: "Everyone" },
+               { hello: { greetings: ['Bonjour', 'Hello', 'Hallo', 'Dzień dobry'] } },
+               "Goodbye", "Hallo"]
+      expected_output = [
+        {
+          hello:
+            [
+              "world",
+              "Everyone",
+              { greetings: ['Bonjour', 'Hello', 'Hallo', 'Dzień dobry'] }
+            ]
+        },
+        "Goodbye"
+      ]
+
+      expect(described_class.merge(input)).to eq(expected_output)
+    end
+  end
+end
diff --git a/spec/models/concerns/group_descendant_spec.rb b/spec/models/concerns/group_descendant_spec.rb
new file mode 100644
index 00000000000..c163fb01a81
--- /dev/null
+++ b/spec/models/concerns/group_descendant_spec.rb
@@ -0,0 +1,166 @@
+require 'spec_helper'
+
+describe GroupDescendant, :nested_groups do
+  let(:parent) { create(:group) }
+  let(:subgroup) { create(:group, parent: parent) }
+  let(:subsub_group) { create(:group, parent: subgroup) }
+
+  def all_preloaded_groups(*groups)
+    groups + [parent, subgroup, subsub_group]
+  end
+
+  context 'for a group' do
+    describe '#hierarchy' do
+      it 'only queries once for the ancestors' do
+        # make sure the subsub_group does not have anything cached
+        test_group = create(:group, parent: subsub_group).reload
+
+        query_count = ActiveRecord::QueryRecorder.new { test_group.hierarchy }.count
+
+        expect(query_count).to eq(1)
+      end
+
+      it 'only queries once for the ancestors when a top is given' do
+        test_group = create(:group, parent: subsub_group).reload
+
+        recorder = ActiveRecord::QueryRecorder.new { test_group.hierarchy(subgroup) }
+        expect(recorder.count).to eq(1)
+      end
+
+      it 'builds a hierarchy for a group' do
+        expected_hierarchy = { parent => { subgroup => subsub_group } }
+
+        expect(subsub_group.hierarchy).to eq(expected_hierarchy)
+      end
+
+      it 'builds a hierarchy upto a specified parent' do
+        expected_hierarchy = { subgroup => subsub_group }
+
+        expect(subsub_group.hierarchy(parent)).to eq(expected_hierarchy)
+      end
+
+      it 'raises an error if specifying a base that is not part of the tree' do
+        expect { subsub_group.hierarchy(build_stubbed(:group)) }
+          .to raise_error('specified top is not part of the tree')
+      end
+    end
+
+    describe '.build_hierarchy' do
+      it 'combines hierarchies until the top' do
+        other_subgroup = create(:group, parent: parent)
+        other_subsub_group = create(:group, parent: subgroup)
+
+        groups = all_preloaded_groups(other_subgroup, subsub_group, other_subsub_group)
+
+        expected_hierarchy = { parent => [other_subgroup, { subgroup => [subsub_group, other_subsub_group] }] }
+
+        expect(described_class.build_hierarchy(groups)).to eq(expected_hierarchy)
+      end
+
+      it 'combines upto a given parent' do
+        other_subgroup = create(:group, parent: parent)
+        other_subsub_group = create(:group, parent: subgroup)
+
+        groups = [other_subgroup, subsub_group, other_subsub_group]
+        groups << subgroup # Add the parent as if it was preloaded
+
+        expected_hierarchy = [other_subgroup, { subgroup => [subsub_group, other_subsub_group] }]
+        expect(described_class.build_hierarchy(groups, parent)).to eq(expected_hierarchy)
+      end
+
+      it 'handles building a tree out of order' do
+        other_subgroup = create(:group, parent: parent)
+        other_subgroup2 = create(:group, parent: parent)
+        other_subsub_group = create(:group, parent: other_subgroup)
+
+        groups = all_preloaded_groups(subsub_group, other_subgroup2, other_subsub_group, other_subgroup)
+        expected_hierarchy = { parent => [{ subgroup => subsub_group }, other_subgroup2, { other_subgroup => other_subsub_group }] }
+
+        expect(described_class.build_hierarchy(groups)).to eq(expected_hierarchy)
+      end
+
+      it 'raises an error if not all elements were preloaded' do
+        expect { described_class.build_hierarchy([subsub_group]) }
+          .to raise_error('parent was not preloaded')
+      end
+    end
+  end
+
+  context 'for a project' do
+    let(:project) { create(:project, namespace: subsub_group) }
+
+    describe '#hierarchy' do
+      it 'builds a hierarchy for a project' do
+        expected_hierarchy = { parent => { subgroup => { subsub_group => project } } }
+
+        expect(project.hierarchy).to eq(expected_hierarchy)
+      end
+
+      it 'builds a hierarchy upto a specified parent' do
+        expected_hierarchy = { subsub_group => project }
+
+        expect(project.hierarchy(subgroup)).to eq(expected_hierarchy)
+      end
+    end
+
+    describe '.build_hierarchy' do
+      it 'combines hierarchies until the top' do
+        other_project = create(:project, namespace: parent)
+        other_subgroup_project = create(:project, namespace: subgroup)
+
+        elements = all_preloaded_groups(other_project, subsub_group, other_subgroup_project)
+
+        expected_hierarchy = { parent => [other_project, { subgroup => [subsub_group, other_subgroup_project] }] }
+
+        expect(described_class.build_hierarchy(elements)).to eq(expected_hierarchy)
+      end
+
+      it 'combines upto a given parent' do
+        other_project = create(:project, namespace: parent)
+        other_subgroup_project = create(:project, namespace: subgroup)
+
+        elements = [other_project, subsub_group, other_subgroup_project]
+        elements << subgroup # Added as if it was preloaded
+
+        expected_hierarchy = [other_project, { subgroup => [subsub_group, other_subgroup_project] }]
+
+        expect(described_class.build_hierarchy(elements, parent)).to eq(expected_hierarchy)
+      end
+
+      it 'merges to elements in the same hierarchy' do
+        expected_hierarchy = { parent => subgroup }
+
+        expect(described_class.build_hierarchy([parent, subgroup])).to eq(expected_hierarchy)
+      end
+
+      it 'merges complex hierarchies' do
+        project = create(:project, namespace: parent)
+        sub_project = create(:project, namespace: subgroup)
+        subsubsub_group = create(:group, parent: subsub_group)
+        subsub_project = create(:project, namespace: subsub_group)
+        subsubsub_project = create(:project, namespace: subsubsub_group)
+        other_subgroup = create(:group, parent: parent)
+        other_subproject = create(:project, namespace: other_subgroup)
+
+        elements = [project, subsubsub_project, sub_project, other_subproject, subsub_project]
+        # Add parent groups as if they were preloaded
+        elements += [other_subgroup, subsubsub_group, subsub_group, subgroup]
+
+        expected_hierarchy = [
+          project,
+          {
+            subgroup => [
+              { subsub_group => [{ subsubsub_group => subsubsub_project }, subsub_project] },
+              sub_project
+            ]
+          },
+          { other_subgroup => other_subproject }
+        ]
+
+        actual_hierarchy = described_class.build_hierarchy(elements, parent)
+
+        expect(actual_hierarchy).to eq(expected_hierarchy)
+      end
+    end
+  end
+end
diff --git a/spec/models/concerns/loaded_in_group_list_spec.rb b/spec/models/concerns/loaded_in_group_list_spec.rb
new file mode 100644
index 00000000000..7a279547a3a
--- /dev/null
+++ b/spec/models/concerns/loaded_in_group_list_spec.rb
@@ -0,0 +1,49 @@
+require 'spec_helper'
+
+describe LoadedInGroupList do
+  let(:parent) { create(:group) }
+  subject(:found_group) { Group.with_selects_for_list.find_by(id: parent.id) }
+
+  describe '.with_selects_for_list' do
+    it 'includes the preloaded counts for groups' do
+      create(:group, parent: parent)
+      create(:project, namespace: parent)
+      parent.add_developer(create(:user))
+
+      found_group = Group.with_selects_for_list.find_by(id: parent.id)
+
+      expect(found_group.preloaded_project_count).to eq(1)
+      expect(found_group.preloaded_subgroup_count).to eq(1)
+      expect(found_group.preloaded_member_count).to eq(1)
+    end
+
+    context 'with archived projects' do
+      it 'counts including archived projects when `true` is passed' do
+        create(:project, namespace: parent, archived: true)
+        create(:project, namespace: parent)
+
+        found_group = Group.with_selects_for_list(archived: 'true').find_by(id: parent.id)
+
+        expect(found_group.preloaded_project_count).to eq(2)
+      end
+
+      it 'counts only archived projects when `only` is passed' do
+        create_list(:project, 2, namespace: parent, archived: true)
+        create(:project, namespace: parent)
+
+        found_group = Group.with_selects_for_list(archived: 'only').find_by(id: parent.id)
+
+        expect(found_group.preloaded_project_count).to eq(2)
+      end
+    end
+  end
+
+  describe '#children_count' do
+    it 'counts groups and projects' do
+      create(:group, parent: parent)
+      create(:project, namespace: parent)
+
+      expect(found_group.children_count).to eq(2)
+    end
+  end
+end
diff --git a/spec/models/namespace_spec.rb b/spec/models/namespace_spec.rb
index 2ebf6acd42a..1bd8e8a5415 100644
--- a/spec/models/namespace_spec.rb
+++ b/spec/models/namespace_spec.rb
@@ -153,6 +153,20 @@ describe Namespace do
     end
   end
 
+  describe '#ancestors_upto', :nested_groups do
+    let(:parent) { create(:group) }
+    let(:child) { create(:group, parent: parent) }
+    let(:child2) { create(:group, parent: child) }
+
+    it 'returns all ancestors when no namespace is given' do
+      expect(child2.ancestors_upto).to contain_exactly(child, parent)
+    end
+
+    it 'includes ancestors upto but excluding the given ancestor' do
+      expect(child2.ancestors_upto(parent)).to contain_exactly(child)
+    end
+  end
+
   describe '#move_dir' do
     let(:namespace) { create(:namespace) }
     let!(:project) { create(:project_empty_repo, namespace: namespace) }
diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index cf26dbfea49..74eba7e33f6 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -1761,6 +1761,21 @@ describe Project do
     it { expect(project.gitea_import?).to be true }
   end
 
+  describe '#ancestors_upto', :nested_groups do
+    let(:parent) { create(:group) }
+    let(:child) { create(:group, parent: parent) }
+    let(:child2) { create(:group, parent: child) }
+    let(:project) { create(:project, namespace: child2) }
+
+    it 'returns all ancestors when no namespace is given' do
+      expect(project.ancestors_upto).to contain_exactly(child2, child, parent)
+    end
+
+    it 'includes ancestors upto but excluding the given ancestor' do
+      expect(project.ancestors_upto(parent)).to contain_exactly(child2, child)
+    end
+  end
+
   describe '#lfs_enabled?' do
     let(:project) { create(:project) }
 
@@ -2178,6 +2193,12 @@ describe Project do
     it { expect(project.parent).to eq(project.namespace) }
   end
 
+  describe '#parent_id' do
+    let(:project) { create(:project) }
+
+    it { expect(project.parent_id).to eq(project.namespace_id) }
+  end
+
   describe '#parent_changed?' do
     let(:project) { create(:project) }
 
diff --git a/spec/serializers/group_child_entity_spec.rb b/spec/serializers/group_child_entity_spec.rb
new file mode 100644
index 00000000000..452754d7a79
--- /dev/null
+++ b/spec/serializers/group_child_entity_spec.rb
@@ -0,0 +1,101 @@
+require 'spec_helper'
+
+describe GroupChildEntity do
+  include Gitlab::Routing.url_helpers
+
+  let(:user) { create(:user) }
+  let(:request) { double('request') }
+  let(:entity) { described_class.new(object, request: request) }
+  subject(:json) { entity.as_json }
+
+  before do
+    allow(request).to receive(:current_user).and_return(user)
+  end
+
+  shared_examples 'group child json' do
+    it 'renders json' do
+      is_expected.not_to be_nil
+    end
+
+    %w[id
+       full_name
+       avatar_url
+       name
+       description
+       visibility
+       type
+       can_edit
+       visibility
+       permission
+       relative_path].each do |attribute|
+      it "includes #{attribute}" do
+        expect(json[attribute.to_sym]).to be_present
+      end
+    end
+  end
+
+  describe 'for a project' do
+    let(:object) do
+      create(:project, :with_avatar,
+             description: 'Awesomeness')
+    end
+
+    before do
+      object.add_master(user)
+    end
+
+    it 'has the correct type' do
+      expect(json[:type]).to eq('project')
+    end
+
+    it 'includes the star count' do
+      expect(json[:star_count]).to be_present
+    end
+
+    it 'has the correct edit path' do
+      expect(json[:edit_path]).to eq(edit_project_path(object))
+    end
+
+    it_behaves_like 'group child json'
+  end
+
+  describe 'for a group', :nested_groups do
+    let(:object) do
+      create(:group, :nested, :with_avatar,
+             description: 'Awesomeness')
+    end
+
+    before do
+      object.add_owner(user)
+    end
+
+    it 'has the correct type' do
+      expect(json[:type]).to eq('group')
+    end
+
+    it 'counts projects and subgroups as children' do
+      create(:project, namespace: object)
+      create(:group, parent: object)
+
+      expect(json[:children_count]).to eq(2)
+    end
+
+    %w[children_count leave_path parent_id number_projects_with_delimiter number_users_with_delimiter project_count subgroup_count].each do |attribute|
+      it "includes #{attribute}" do
+        expect(json[attribute.to_sym]).to be_present
+      end
+    end
+
+    it 'allows an owner to leave when there is another one' do
+      object.add_owner(create(:user))
+
+      expect(json[:can_leave]).to be_truthy
+    end
+
+    it 'has the correct edit path' do
+      expect(json[:edit_path]).to eq(edit_group_path(object))
+    end
+
+    it_behaves_like 'group child json'
+  end
+end
diff --git a/spec/serializers/group_child_serializer_spec.rb b/spec/serializers/group_child_serializer_spec.rb
new file mode 100644
index 00000000000..5541ada3750
--- /dev/null
+++ b/spec/serializers/group_child_serializer_spec.rb
@@ -0,0 +1,110 @@
+require 'spec_helper'
+
+describe GroupChildSerializer do
+  let(:request) { double('request') }
+  let(:user) { create(:user) }
+  subject(:serializer) { described_class.new(current_user: user) }
+
+  describe '#represent' do
+    context 'for groups' do
+      it 'can render a single group' do
+        expect(serializer.represent(build(:group))).to be_kind_of(Hash)
+      end
+
+      it 'can render a collection of groups' do
+        expect(serializer.represent(build_list(:group, 2))).to be_kind_of(Array)
+      end
+    end
+
+    context 'with a hierarchy', :nested_groups do
+      let(:parent) { create(:group) }
+
+      subject(:serializer) do
+        described_class.new(current_user: user).expand_hierarchy(parent)
+      end
+
+      it 'expands the subgroups' do
+        subgroup = create(:group, parent: parent)
+        subsub_group = create(:group, parent: subgroup)
+
+        json = serializer.represent([subgroup, subsub_group]).first
+        subsub_group_json = json[:children].first
+
+        expect(json[:id]).to eq(subgroup.id)
+        expect(subsub_group_json).not_to be_nil
+        expect(subsub_group_json[:id]).to eq(subsub_group.id)
+      end
+
+      it 'can render a nested tree' do
+        subgroup1 = create(:group, parent: parent)
+        subsub_group1 = create(:group, parent: subgroup1)
+        subgroup2 = create(:group, parent: parent)
+
+        json = serializer.represent([subgroup1, subsub_group1, subgroup1, subgroup2])
+        subgroup1_json = json.first
+        subsub_group1_json = subgroup1_json[:children].first
+
+        expect(json.size).to eq(2)
+        expect(subgroup1_json[:id]).to eq(subgroup1.id)
+        expect(subsub_group1_json[:id]).to eq(subsub_group1.id)
+      end
+
+      context 'without a specified parent' do
+        subject(:serializer) do
+          described_class.new(current_user: user).expand_hierarchy
+        end
+
+        it 'can render a tree' do
+          subgroup = create(:group, parent: parent)
+
+          json = serializer.represent([parent, subgroup])
+          parent_json = json.first
+
+          expect(parent_json[:id]).to eq(parent.id)
+          expect(parent_json[:children].first[:id]).to eq(subgroup.id)
+        end
+      end
+    end
+
+    context 'for projects' do
+      it 'can render a single project' do
+        expect(serializer.represent(build(:project))).to be_kind_of(Hash)
+      end
+
+      it 'can render a collection of projects' do
+        expect(serializer.represent(build_list(:project, 2))).to be_kind_of(Array)
+      end
+
+      context 'with a hierarchy', :nested_groups do
+        let(:parent) { create(:group) }
+
+        subject(:serializer) do
+          described_class.new(current_user: user).expand_hierarchy(parent)
+        end
+
+        it 'can render a nested tree' do
+          subgroup1 = create(:group, parent: parent)
+          project1 = create(:project, namespace: subgroup1)
+          subgroup2 = create(:group, parent: parent)
+          project2 = create(:project, namespace: subgroup2)
+
+          json = serializer.represent([project1, project2, subgroup1, subgroup2])
+          project1_json, project2_json = json.map { |group_json| group_json[:children].first }
+
+          expect(json.size).to eq(2)
+          expect(project1_json[:id]).to eq(project1.id)
+          expect(project2_json[:id]).to eq(project2.id)
+        end
+
+        it 'returns an array when an array of a single instance was given' do
+          project = create(:project, namespace: parent)
+
+          json = serializer.represent([project])
+
+          expect(json).to be_kind_of(Array)
+          expect(json.size).to eq(1)
+        end
+      end
+    end
+  end
+end