One way to go about it is to drag whatever you are after to the quick macro bar. Before editing, that generally shows the whole thing. That will show the row id as the long string of numbers and letters that you can replace with $0 (or whatever number). If you roll it from there, put your cursor in the cat entry box, and then hit the up arrow, it will show the shortcut that method uses of calling that roll.
You could also right click on something and select "Inspect Element" from the drop down. This will show you the html code of that section of the sheet where you can get the repeating section label (the html label, not what is shown as a section title on the sheet, though they may be the same) and the individual input attribute names.