Mastan,
I guess you are searching for a where-used list for the PRT's in the routings.
Try the following:
1. CRVE_B-EQUNR = equipment number, CRVE_B-OBJTY = FH, extract CRVE_B-OBJID.
2. If you want to see only routing assignments, PLFH-PLNTY = 'N', PLFH-OBJID = CRVE_B-OBJID. Extract PLFH-PLNNR, PLFH-ZAEHL.
3. Access MAPL using PLNNR and ZAEHL.
Good Luck,
Rajen