laravel many to many relationship between 3 tables

I have 3 tables category,product and store.One product can be in multiple categories and Store can have multiple categories and product.

I know how to setup many-to-many relationship between 2 tables in laravel using pivot tables.However,regarding 3 tables,its getting a bit complicated.What is the best approach to setup many-to-many relationship between 3 tables using laravel framework ?

via Chebli Mohamed