Is there a way to filter link field in web forms?

I have web form in which there is a Link field. That Link field is Linked with a doctype called Policy Master. If Policy Master which has Approved status should only appear in that web form. How to filter that in web form. I tried to filter in main doctype but it is not working in web form.

Also how to filter a Link field based on what is selected in other field.

Any Update