So i created a new model and i did this mapping
so if AccountNum 1 has invoice1 and invoice2 and accountNum 2 has Invoice3
i should get 2 headers one for accountNum1 and one for accountNum2 and inside each one is all it's invoices
but instead i'm getting 3 headers AccountNum1 with Invoice1 then AccountNum1 with Invoice2 then AccountNum3 with Invoice3
sth like below, so what did i do wrong?