code: def add_filter_by_client(self, query, out_params):
          
          current_client = logged_in_client(self.context)
          if current_client:
              query['getClientUID'] = api.get_uid(current_client)
          elif self.request.form.get("ClientUID", ""):
              query['getClientUID'] = self.request.form['ClientUID']
              client = api.get_object_by_uid(query['getClientUID'])
              out_params.append({'title': _('Client'),
                                 'value': client.Title(),
                                 'type': 'text'})
docs: Applies the filter by client to the search query