Receivable code combination and/or BSV as SLA source

Summary

Need ability to derive BSV/company codes on the AR tax line from the receivable line

Content

I've received the following tip on deriving the BSV on the AR tax line for intercompany invoices but we're struggling to find the AR SLA source for the receivable line and/or BSV - can anyone point us in the right direction, pls:

We encountered a similar challenge with Intercompany, so built a SLA rule that would drive the BSV for tax based on the BSV for the Receivable line..

Ideally we wanted to use the Revenue line but struggled locating a "Revenue Distribution" seeded source (and ran out of time to see if we could build a custom SLA formula)..