Confused with category scope in Magento 2

I have a Magento store with 3 stores scope (Brazil, USA and Global) and just one root category, but now I have a main category called ‘Off Price’. In this category I need to put specific products for Brazil, USA and Global, but, for example, when i remove a product from Brazil a need to let this product in USA and Global, but the products is been removed in all web sites.

What I’m doing wrong?