Moving Line-Like Curves Whist keeping Data Structure

Hi there,

I'm trying to do something which seems simple enough but I can't get my head round to getting it to work.

I've got a list of 24 branches each containing different amount of curves. I'd like to move all of these along the 40 'Z' vectors. The only way I can get it to work is by flattening the list but then I loose tree structure.