backend/src/main/java/core/api/controller/TaskController.java

@@ -72,7 +72,11 @@ public class TaskController {
             return ResponseEntity.status(404).body(new SimpleStatusResponse("failed"));
         }
 
-        return ResponseEntity.ok(taskgroupPermissionResult.getResult().getTasks().stream().map(TaskEntityInfo::new));
+        List<Task> tasks = new ArrayList<>();
+        for(Task task : taskgroupPermissionResult.getResult().getTasks()) {
+            if(task.getParent() == null) tasks.add(task);
+        }
+        return ResponseEntity.ok(tasks.stream().map(TaskEntityInfo::new));
     }
 
     @PutMapping("/tasks/{taskgroupID}")