I've now read through the post and I think I see what it's trying to do.
I'm using two tables so I should be able to just do what you suggest as follows:
" - categories query (uncheck output option) - repeat categories query (select the output fields here, which you want to show later on the page); Enable output option. - (inside the repeat) products query filtered by category ID. "
One question though, how do I do the second point above and create a repeat step just using Server Connect? I can do it with App Connect but that requires something on the page to repeat.
If you can let me know or point me at a video showing how to repeat without App Connect I'd be most grateful.