HR Position herarchy for Blanket purchase Agreements with cost centre validation ?

Hello,

We are on Oracle R12.1.3

We are extensively using the buyer work center feature.

We are building an approval heirarchy for Blanket purchase agreement using HR position heirarchy , approval groups , approval assignments, approval management engine etc.

We have a requirement where in BPA will store cost centre may be in a DFF ( one of segments of chart of accounts ), which needs to validated with approval groups. ( similar to requisition heirarchy )

To elaborate, The buyer will create a Blanket purchase Agreement and enter the cost centre may be in a descriptive flex field.

The BPA must be sent for approval to the budget owner for this cost center. ( The amount limits and cost centers which the budget holders can approve can be set up in approval groups and approval assignments.)