I am looping on a list with documents of type A.
The output is a list of documents of type B.

Theres a mapping step for each iteration to map an item of type A to an item of type B.

However, what I want is for example when I come accross an element in the list A (whilst looping) I want to to have 2 or 3 elements of type B in the output list.

If I do a simple mapping there is a one-to-one mapping. I want to be able to do a one-to-many mapping also.

what would be the best way to approach this?

many thanks.

My suggestion would be use appendToDocumentList public service.