Receiving and shipping PO for a group of department

Hello,

Looking for a way to handle this.

Our users creates Requisitions and PO for a whole department, example 730002-TI.  The budget is controlled at that level. Requisitions and POs are approved.

The department has few sub-department. When they receive the stock, the head department distributes to each sub-department. 

Sub-departments example 730002-TI-1020, 730002-TI-1030...

How can we handle at the reception or shipment without having to modify the PO,

Actually, they redo the PO and the requisition and we have a lot of problems.

Usually, it does not concern the stocks, it is expense.

Thanks!