Two dropdown widget dependency with Supabase

hello..

I am creating two dropdown widgets that have dependencies.

The sources are the two tables Province and GuGun in Supa Base.

I'm taking this data and constructing a dropdown menu, and individually it's working fine.

However, we would like to link it so that the GuGun widget value appears optionally when selecting the Province widget.

However, when selecting the filtering function in the second dropdown GuGun for integration, the widget is not selected as shown in the attached image.

Experts, what should we do?

Thank you for your reply.