In this video, I demonstrate how we can edit and create user groups and access rights with the goal of modifying a salesperson's access in the Contact app.
This can be done without using Odoo's Studio app.

This video won't take every use case, requirement or other customizations.

Access rights can be difficult, so I always recommend working and testing in a separate environment to preserve the integrity of a production environment.

The domain I used in this video was:

['|',('supplier_rank','=','0'),('supplier_rank','=',False),'|','|','|','|','|','|',('create_uid','=',user.id),('user_id','=',user.id),('user_id','=',False),('create_uid','=',False),('parent_id.user_id','=',user.id),('parent_id.user_id','=',False),('parent_id.create_uid','=',user.id)]