Hello,
Please note that in a Material document the partner profit center (MSEG-PPRCTR) is the accounting data and comes from the account assignment object. Normally, it comes from the profitability segment document.
You can check this in MSEG table.
As response to your question, i can suggest to define the G/L account associated as cost
element and assign partner profit center.
As a consequence, it will be populated in the material document and as a consequence in the FI document.
Indeed, I should add that in some cases it depends on the transaction used.
For example, In MIGO, the field selection is independent, while in the classic transactions for
posting goods movements (MB*), the partner profit center is transferred to the interface for accounting depending on the field selection of the movement type for the "Profit Center" field.
So may I suggest you to to set "profit center" to be optional field and then (MB*) would have the same partner profit center assignment as MIGO transaction.
I hope this information helps you to understand the partner profit center assignment.
Cheers,
Siwar