My application version is AX 2012 R3 on RTM(6.3.164.0).
Module is “Account Payable”.
Common->Vendors->All Vendors.
Then highlighing one vendor and after that click Transaction from action pane(vendor->transaction).
After that new from with that vendor opens.
Then if we click “Show open only” that shows open transactions.(Shows 5 open transaction).
now to settle open transaction again go to All vendor form and from action pane click(invoice->settle->settle open transaction).
This shows only two transactions.
Two of them are payment transaction (AP->journal->Payment->Payment journal).
Three of them are Invoice transaction(AP->Journal->Invoice->Invoice journal).