Try using Supplier Analysis window (Financials > Accounts Payable > Supplier Analysis). Here you have to search for the supplier ID first. Then all the invoices created for that supplier will be listed down (make sure that you have set the Auto Populate check box on header). You need to find the invoice and then select right mouse button Payments per Invoice/ Prepayments. With this option you can see all the payment details related to that invoice with vouchers and dates. I find this window very useful as it shows each actions performed in relation to invoices (payments, cancellations etc)
Also if you check under Accounts Payable in navigator, you will find some other useful windows too. For example, in AP Supplier Invoices Analysis (Financials > Accounts Payable > Analysis > AP Supplier Invoice Analysis) you can search for the invoice and use the same RMB options to check the payments.