Show all groups in timetable view

aleksis/apps/chronos/util/chronos_helpers.py

@@ -106,10 +106,7 @@ def get_classes(user: "User"):
             lessons_count=Count("lesson_events"),
             child_lessons_count=Count("child_groups__lesson_events"),
         )
-        .filter(
-            Q(lessons_count__gt=0, parent_groups=None)
-            | Q(child_lessons_count__gt=0, parent_groups=None)
-        )
+        .filter(Q(lessons_count__gt=0) | Q(child_lessons_count__gt=0))
         .order_by("short_name", "name")
     )