How to Trigger BPM Approval for a Custom Project Role (Center Director)?

hello all,

We have a business requirement where project budget approvals must be done by the Center Director. We created a custom project role called “Center Director” and center director assigned as Project resources accordingly. However, in the BPM approval rule, we only see standard roles like Project Manager and Team Member in the payload. The custom role does not appear.

How can we configure the BPM approval to trigger for whoever holds the “Center Director” role in the project?

Is it possible to achieve this using supervisor hierarchy or do we need to set up some other hierarchy builder? Any suggestions or best practices on handling approvals for custom roles in BPM would be highly appreciated.