Cash Discount account structure is
main account - dept - vendor.
Vendor financial dimension is set in vendor master.
Dept is a fixed value set in Chart of Accounts.
There are no financial dimension variations while posting both PO Invoice and Payment journal. Still it made two cash discounts.
There are two more similar cases where cash discount was split.
During these postings, dept value was not set in Chart of Accounts and it made two separate financial dimension combinations with main account and vendor
Here is a snapshot of one of it.
Thanks,
Lakshmi