Now, I have a custom record. The record has a custom field.

List/Record : Customer

I need a second custom field to select an

Address

from the Customer custom record. How can I add this second field in order to filter it by the customer field?

address subrecords have no relations to customers

Thanks! So now my customer field is

List/Record : Entity

and my address field is

List/Record : Address Book

you can now use the sourcing/filtering option on the addressbook field

Done!