Hierachy of Data

Hi there, I am relatively new to Bubble and the database structure . I was hoping someone could assist me with a conundrum I can’t seem to make sense of. I am creating an app where users can log in and go through catalogues of items, and say whether they have them or want them - but these items come with accessories. Some of the accessories are the same for the items, and sometimes they are different but the user, when saying they have the item need to also tick off that they have the correct accessories as well - related to the correct item. I have created the repeating group, but if I mark in the database that the user has the shoes, it is not relating to the item so it applies it to all the items which need shoes.

Could someone guide me on how I can save the correct accessory, under the correct item, as a user?

Thanks so much

Perhaps these videos can help with structuring in general