How to create custom security for cross department

Summary:

We have two independent employee groups with separate HR security profiles. HR users in each group should only see their own employees. However, some employees in Group A report to line managers in Group B. The line manager can access the employee through Manager Hierarchy Security, which is expected. Our additional requirement is that the HR users in Group B should also be able to access those cross-group employees, while still not having access to the rest of Group A. Has anyone implemented this requirement using standard Oracle Fusion HCM security? Would this require a custom Person Security