Armor slots

guys, tell me how to make armor that will fit on one slot (body, arms + legs). I can't make such a model as in this mod, I want to complement it, but my armor doesn't see my arms, only my body and legs. And I need three body parts to work in one armor slot

how it should look like:

What it looks like now: (there are hands on the model, but it does not display and I need to make it display)