Stock Item Supplier

SOLVED

Hello,

We have a Purchase Order layout that I'm trying to configure to use the Stock Item Supplier Code (From Stock Item details > supplies tab). The issue I'm having is getting this to show the correct stock item supplier code if there are multiple suppliers against a product. 

I've tried a huge variety of joins but this comes across different issues (I.e. it changing to child outer joins, adding multiple keys, etc) and I'm not too sure why.

I understand why I'm having the issue of it not pulling the correct stock code because the tables are currently linked from POPOrderReturnLine > Stock Item > StockItemSuppliers. This obviously means it doesn't know which supplier to associate it with but is there a specific table and field should I link the StockItemSupplier table too?

Thank you in advance.