sorry to bother you, but I am doing subcontract processes since 1997, and I do not get your scenario.
In a standard scenario you order a finished material from your subcontractor and you send him the components.
The components are just booked into subcontractor stock of your sending plant.
The external subcontractor does the operations in his system and has no connection to our SAP. When we get the finished material we receive it and consume the components at the same time. All this is done in the ordering plant.
Now coming to intercompany process. Both parties are in one SAP system.
If the components are send to your subcontracting plant, then they are still in subcontractor stock (special stock indicator O) in your sending plant.
How can the subcontracting plant receive the components in SAP?
if you have a sales order and this is a make to order process, the sales order is in the same plant as your ordering plant for the subcontract order.
If you could be so nice and could your process explain in this detail, maybe then it is easier to understand.