In MongoChart, Filter pane is not working for lookup collection field

In MongoChart, Filter pane is not working for lookup collection field.
**I have two collection. Datasource is First collections and used lookup for Second collection. I am trying to filter the field value which is from second collection but filter pane is not working.

Note:
** I tried second collection as datasource to chart and applied filter to same field , it is working .**