Hi Yuichi.
I assume you are referring to Open AP/AR Items. If you go to Receivables workcenter, you can use the Report "Account Receivables - Open Items", which can be used. Same exists for Payables.
In addition we tried used the concept "work comes to the end user". So you get tasks in the Receivables -> Work. Here you can use the filter "Clearing Receivables Tasks". (Maybe you should get familar with the work center "Work". I personally believe this is one of the innovations in ByDesign).
Hope this helps. If you have further questions, please let me know. Otherwise please mark the question as answered.
Best regards
Marlene