How to show transaction Class header in a Workbook?

I'm trying to get a dataset of all transactions by class. We are selecting class by transaction body but the analytics datasets only seem to make class available on the transactions lines. In order to link it to another table, I'd like to have a list of transactions(Headers) by class. If I could group the transaction lines by class, I could probably make that work.

I don't suppose this is possible, is it?

Thanks!