docs: clarify dict2items usage in loops with group module (follow-up to ansible#85897) (#3124)

* docs: clarify dict2items usage in loops with group module (follow-up to ansible#85897)

* docs: merge dict2items group example into existing section (per review)

* docs: replace tag_data example with nested server_configs dict example (per review)

Author: GabrielOvie

docs/docsite/rst/playbook_guide/playbooks_loops.rst

@@ -144,14 +144,23 @@ To loop over a dict, use the  :ref:`dict2items <dict_filter>`:
 
     - name: Using dict2items
       ansible.builtin.debug:
-        msg: "{{ item.key }} - {{ item.value }}"
-      loop: "{{ tag_data | dict2items }}"
+        msg: "{{ item.key }}: {{ item.value.ip_address }} {{ item.value.role }}"
+      loop: "{{ server_configs | dict2items }}"
       vars:
-        tag_data:
-          Environment: dev
-          Application: payment
-
-Here, we are iterating over `tag_data` and printing the key and the value from it.
+        server_configs:
+          web_01:
+            ip_address: "10.1.1.50"
+            role: "frontend"
+          db_01:
+            ip_address: "10.1.1.100"
+            role: "backend_db"
+
+Here, we are iterating over `server_configs` and printing the key and selected nested fields.
+
+If the values in the dictionary are themselves dictionaries (for example, each group maps
+to a dict containing a ``gid``), remember that after applying ``dict2items`` each loop item
+has two attributes: ``item.key`` and ``item.value``. Access nested fields via
+``item.value.<field>``.
 
 Registering variables with a loop
 ---------------------------------