Depending on your requirement, you can:
- simply define the profit center to be entered based on the GL account used - OKB9
- define a derivation rule in TRM if you want to choose dinamically the profit center
-> FSCM -> TRM -> Transaction Manager -> Accounting -> Link to other accounting Assignments -> Additional Account Assignments -> Define derivation of additional account assignments
Even though I would not reccomend, you also have a 3rd option to use the available BADI's in case your requirement is more complex
Regards,
mcc