code: def filter_queryset(self, request, queryset, view):
          
          if request.user.is_staff:
              email = request.query_params.get('email', None)
              username = request.query_params.get('username', None)
              query_parameters = {}
  
              if email:
                  query_parameters.update(email=email)
              if username:
                  query_parameters.update(username=username)
              if query_parameters:
                  users = User.objects.filter(**query_parameters).values_list('id', flat=True)
                  queryset = queryset.filter(user_id__in=users)
          else:
              queryset = queryset.filter(user_id=request.user.id)
  
          return queryset
docs: Apply incoming filters only if user is staff. If not, only filter by user's ID.