Add duplicated set filter and documentation (#72729)

Co-authored-by: Kerry <kerry@flatline-studios.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/docs/docsite/rst/user_guide/playbooks_filters.rst b/docs/docsite/rst/user_guide/playbooks_filters.rst
index 984de55e4b..9ea4104440 100644
--- a/docs/docsite/rst/user_guide/playbooks_filters.rst
+++ b/docs/docsite/rst/user_guide/playbooks_filters.rst
@@ -978,6 +978,14 @@ To get the symmetric difference of 2 lists (items exclusive to each list)::
     {{ list1 | symmetric_difference(list2) }}
     # => [10, 11, 99]
 
+To get the duplicate values from a list (the resulting list contains unique duplicates)::
+
+.. versionadded:: 2.11
+
+    # list1: [1, 2, 5, 1, 3, 4, 10, 'a', 'z', 'a']
+    {{ list1 | duplicated }}
+    # => [1, 'a']
+
 .. _math_stuff:
 
 Calculating numbers (math)