Fixes #7205: Handle `null_option` when getting selected form values in `applied_filters` template tag

docs/release-notes/version-3.0.md

@@ -10,6 +10,7 @@
 * [#7176](https://github.com/netbox-community/netbox/issues/7176) - Fix issue where query parameters were duplicated across different forms of the same type
 * [#7188](https://github.com/netbox-community/netbox/issues/7188) - Fix issue where select fields with `null_option` did not render or send the null option
 * [#7193](https://github.com/netbox-community/netbox/issues/7193) - Fix prefix (flat) template issue when viewing child prefixes with prefixes available
+* [#7205](https://github.com/netbox-community/netbox/issues/7205) - Fix issue where selected fields with `null_option` set were not added to applied filters
 
 ---
 

netbox/utilities/forms/utils.py

@@ -120,11 +120,20 @@ def get_selected_values(form, field_name):
     if not hasattr(form, 'cleaned_data'):
         form.is_valid()
     filter_data = form.cleaned_data.get(field_name)
+    field = form.fields[field_name]
 
     # Selection field
-    if hasattr(form.fields[field_name], 'choices'):
+    if hasattr(field, 'choices'):
         try:
-            choices = dict(unpack_grouped_choices(form.fields[field_name].choices))
+            grouped_choices = [(k, v) for k, v in field.choices]
+
+            if hasattr(field, 'null_option'):
+                # If the field has a `null_option` attribute set and it is selected,
+                # add it to the field's grouped choices.
+                if field.null_option is not None and field.null_option in filter_data:
+                    grouped_choices.append((field.null_option, field.null_option))
+
+            choices = dict(unpack_grouped_choices(grouped_choices))
             return [
                 label for value, label in choices.items() if str(value) in filter_data
             ]