How to use a constraint in a dropdown

Hello everyone.

I’m trying to do the following:

I need to display only users (named as clientId)who have a relation with merchantId on the subscription’s table, so the dropdown will only show users these users.

However, it is showing all the users on the table subscriptions . How can I do this filtered using do a search? I struggling with it

If someone is interested in testing this part of the solution, go to merchant dashboard>Popup create_a_appointment

Link of the editor:Loopr-semcodar-24946 | Bubble Editor