How to Map one Cost center to Two different BU

Summary:

I have to Map one cost center to Two different BU for Kicking the Approval Rule based on the Cost center Manager to two different persons.

Content (required):

I have a Cost center which were defined under the Manage Department with a Common data set and one Cost center owner has been tagged to that Cost Center as manager to whom the Requisition approvals are going right Now.

But there is a requirement that approvals should go to two different persons based on the Procurement BU who will be tagged as Cost center manager.

I had tried to do the same via Department set tagged to BU but it doesn't working.