Automatically set the Primary Responsibility to Group Manager

When creating a Ticket form, we set a default "Responsible" value to a group, is there also a way to automatically set the "Primary Responsibility" to the manager of the group instead of having that value stay 'Unassigned'?

I would think this could be part of an Automation rule, but I would like to be generic about the rule, and just have the assignment be the current manager of the responsible group, and not have hardcoded users in the assignments.