AKA Product Folders.
You can have unlimited nested categories. That means you can have a product, inside a category, which is inside a category, which is inside a category, which is inside. . . you get the picture.
To create a Category, go to the correct product catalogue (either the Standard Products (aka Storefront Products or Generic Products) or a particular Clients Products page. At the top of the page you will see a ‘New Category’ button.
To place Products inside a Category you need to EDIT the product and select the Category from a drop down.
To organise and position a Category and Products in a Category you can drag and drop the objects around the page.
You can also control who can see the Category and limit it to particular Departments. NOTE: You can also do this while you are editing a Department.