NW BPM in PI7.3.1 single stack

HI Experts,

Is any one done NW BPM sceanrio like ,

Source side : Header & Details file

Target Side : IDOC

i can do in ccBPM as : Fork (Receiver step 1 + Receiver Step 2) --> Transfermation --> Send step

But, how to design in NWDS this scenario ?

Regards,

Deva