We're a manufacturing company and we build our products.
We need to be able to assemble a composite item that is required to be in stock for another composite item to be assembled.

Ex: I'm selling 3 types of tables but they all have the same legs. So the legs are a composite item (wood, glue, screws) but the table is also a composite item made of 4 legs and 1 top. How can I, in the invoice, assemble the legs I need in order to assemble the Table?