Strange one, but if you wanted a layout that displays as
Shirts
[ Product | Product | Product ]
Jeans
[ Product | Product | Product ]
But have it dynamic, you would use nested collections, but for some reasons the “product” multi-reference for “categories” doesn’t display in nested collections. You have to create a new multi-reference field called “products” and copy the “product” field to achieve this.
I think the default “product” field should show up in nested collections, it makes no sense to have to create a new multi-reference to achieve this?