Concurrent program to set user profile for required business group

Hi All,

We have following scenario,

4 Business Groups , 4 Ledgers ,

Common  Buyer for all 4 business groups, now to make purchase order we have to define buyer / person in each BG, need to define multiple responsibilities, multiple users, this increases our licensing cost, is there any way by which we can set up user profile by concurrent program based on his requirement means if user need to work on BG-1 then he will submit this concurrent request and Ledger ID, HR Security profile, MO OU, MO Security profile gets set accordingly, by doing this user will not need to change responsibility and we can manage with minimum user license.