Please help on this mapping header to item level

I need some help on the following

In each line item I need to check If Z1MARA2>MFRPN  is not blank and then check  from header IF E1EDKA1.PARVW= MN then copy E1EDKA1>NANME1  to each item level . This one is working with the following mapping when data  Z1MARA2>MFRPN exist in all the line items exist

But when there is no Z1MARA2>MFRPN in any of the line items , it copying to all the line items. I need to copy only the respected line item where Z1MARA2>MFRPN  is present . What i need to change this mapping

mfrpn-mapwithdefault>equals>consta- not then

Parvw equals+MN then copy Name1 >removecontext  copyvaue(0) mapwithdefault  > useoneasmany >

                                                                                                                             e1edp01        >                 splitbyvalue _target        

                                                                                                                                  e1edp01>

Thanks for your help