Hello Josh,
Select one Customer Ledger Entry, open the NAVIGATE tab, and click on Applied Entries. This will show all applications for that one customer ledger entry.
Closed entries in NAV mean that one entry (payment) is applied to another invoice entry. You can see that on the remaining amount on the Customer Ledger Entry. If the Remaining amount is different than the Original Amount, you have a partially closed entry, and your entry will be Open, and if it is 0, your Customer ledger entry is only then closed.
If you want to see all posted payments, you can filter Customer Ledger Entry with Document Type filters.
Also you can filter Detailed Customer Ledger Entry table/page and find entries with filters Entry Type = Initial Entry, and Document Type = (blank, or payment)
and you will filter all payments that are posted, and if you change your filter on the Entry Type column on the Application, you will see all payments that are closed.
I hope it was helpful,
Greetings