You can use the posting info search for a number of reasons. It shows the posting information of payslip details and can be filtered and sorted by a number of fields.
To check what constitutes a journal entry
Note which journal entry you are looking to breakdown, the payrun ID and the P&L/Balance Sheet Account you are reviewing
Navigate to Payroll Administration > FAQ and Troubleshooting > PR-Posting Info Payslip Detail Search Results
Select the filters you require: Balance Sheet Account/P&L Account and the Pay Run ID in question
Check the totals match with the totals of the journal you are reviewing, you will be able to see what payslip details make up a posting journal entry.