On which table, Books or Subjects, is the layout based where you perform your find?
On which table, books or Subjects, is the layout based that you want to use for your report?
The find layout is based on Books.
The report is based on Subjects so that I can have that as the body of the grouping
(I should clarify that it is actually subject occurences because I make it sound like it is just subjects which would need to be a many-to-many, but I won't get into that. Trust me, it is a one-to-many.)
So your find is finding book records, but your report needs to list the records from the related join table...
Perform the find from the report layout. This finds all join table records linked to a book record with the specified criteria.
Perform the find on your books layout, then use Go To Related Records with the "match found set" option to pull up all the matching join table records on your report layout.
Both methods should produce the same found set of join table records.
I have tried GTRR using the Match Found Set, but it isn't using the same records. Could there be another setting I'm not doing right? That seemed the obvious choice, but it doesn't work. I really cannot perform the FIND from the report layout (or, I should say, prefer). It wouldn't be as clean as I would like for this particular application.
It should be quite simple to perform the find form the report layout's context. You may need to create a different layout for this that also refers to the join table in order to have the correct fields in place if you perform your finds manually. With a scripted find where you enter/select criteria in global fields, you can create a script that just pops up a small window for specifying the criteria and then clicking a button in this window closes the small window and takes you to the report layout where it performs the find for you.
But GTRR should work. If it doesn't there's a problem with either your data, your relationship, or you aren't selecting the correct options for the GTRR step. But I can't tell you which from here unless you provide all of those details.
Note that I am assuming that all your find criteria is entered in fields from the Books table, not a table related to it. If you are specifying criteria in related records, then this could also be why your GTRR didn't work as expected.
I felt like the GTRR was the right and best option, but had tried it. I started from scratch and thought it through more carefully and it worked. Not quite sure what I did the wrong the first time, but it works like I thought it would/should now. Thanks for helping me think through it.