Filtered account report

[AC]

I was looking at some of my loans and wanted to get an idea of how much
I paid in interest to each loan over their life.  I've got one account
that collects the amount of loan interest every time I pay (as part of a
split transaction) while the principal portion of the payment goes to
the specific loan account.

There's a mix of different loans in the one interest paid account (Loan
A, Loan B, Loan C, etc.) and I wanted to see, for example, only the
interest paid on Loan B.

I thought I could run an account report on a search window but that
doesn't work because it also finds the principal payments and tabulates
them as well in the final total.

What report and/or filtering mechanism could/should I use to show this
information?