Hi
The clearing transactions like F-44 and F-32 always refer BSEG and not FAGLFLEXA. So unless, you populate profit center on each and every single customer/vendor line item, it would not be possible to have profit center as a selection crieterion for Open Item Clearing. You would have to build in substitution rule to have vendor and customer line item populated with profit center in entry view. Keep in mind, the profit center substitution has to be in line with your business design.
regards
Sanil Bhandari