Where does the cash flow segment for a purchase order matched invoice come from?

PO charge account and PO accrual account act as the cash flow source for purchase order (PO) matched invoices.

In Payables, the invoice distribution account has cash flow segment. Here, the PO charge account and the PO accrual account are listed as the sources.

For example, use the item category and PO category to define the cash flow segment.

Do this for an expense account on the Category Account Definition page. Use the workflow to get the cash flow segment. The value matches the invoice distribution account.