code: def _parent_queryset(self):
          
          parent = self._resource.parent
          if hasattr(parent, 'view'):
              req = self.request.blank(self.request.path)
              req.registry = self.request.registry
              req.matchdict = {
                  parent.id_name: self.request.matchdict.get(parent.id_name)}
              parent_view = parent.view(parent.view._factory, req)
              obj = parent_view.get_item(**req.matchdict)
              if isinstance(self, ItemSubresourceBaseView):
                  return
              prop = self._resource.collection_name
              return getattr(obj, prop, None)
docs: Get queryset of parent view.
  
          Generated queryset is used to run queries in the current level view.