Mapping problem

Hello,

I have source like below

Message

articleno

subMessage

quantity

submessage

quantity

target message

no of occurence of target should be equal to submessage occurence but while doing this getting error as cannot produce target message for articleno

as articleno is having only one entry in this case it is not able to generate second occurence

I hope its clear

Very helpful some one can provide solution

Rajesh