Your company uses a third-party call center service. Customer Service Reps for this service are not direct employees of your company but still need access to your IDI environment.
Preferably, supervisors in the call center will manage on their own the creation of user accounts and resetting passwords for their own employees.
In addition, since these users are not employees of your company, you want them to be forced to change their passwords every 30 days instead of every 90 days as an added security measure.
Solution
You create a new user Domain in Security called Call Center. When you create this Domain you set the Domain Password Settings to expire passwords after 30 days.
Once created you add User accounts for the supervisors at the call center and add them to this new domain.
These supervisors now can begin to add and manage User accounts for their employees without being able to see or affect accounts in your default domain.