Community Tutorial: Creating a Custom Asset Type with its own Editor in C++

I am currently working on a plugin and I am wondering if it is possible to create “nested categories”. What I mean by that is instead of having a single category like for example “Inventory”, I would like to have another category in that category, for example: “Inventory → Items”. Do you know (or anyone else) how I would achieve something like this? I have played around with Asset Tools for a bit but was not able to find a solution so far.