How to get a field with a relationship in a view
Follow this steps:


Add a relationship of brand to the view. This will get you to display the properties and fields of the brand entity.
Add another relationship for the brand field which references to the category entity using the entity reference field. This relationship should use the previous relationship (like nested relationships).
Now you should be able to display the properties and fields of the category entity as well.


Note: I've written this generically; it should work for any type of entities (e.g. Nodes, Users, Files, Taxonomy, etc.)