Can Out of the box Eliminations data source in FCC be split in two parts? How?

The adjustment period data in our Client's case is booked in P12 itself and then it is separated by a different data source specific for P13. But for eliminations, since all OOTB eliminations get booked in one Data Source member ‘FCCS_Intercompany Eliminations’ by default, they want it to be split in two parts. One for P1 to P12 OOTB eliminations and another for P13 eliminations. What would be the feasible way to achieve this - CC Rule/ODR/Backend rule change/something else?