Security requirement for multiple assignment

At our organization, we are implementing person based security using AOR by organization hierarchy.
(This is configured and working as expected.)

However, we have additional security requirements for employees with multiple assignments.
At our organization, it’s common for employees to have multiple (active) assignments in different departments.

The desired security requirement around this is where the employee has multiple assignments, the HR Specialist should have
• Edit access for the assignment that falls within their assigned AOR
• View access for any assignment that is outside their assigned AOR

How do we achieve this to meet the organizations requirement?