Include two entities in a single class Sonata Admin Bundle

Include two entities in a single class Sonata Admin Bundle

I have a Product table and a Brand table. Brand table contains a product
id. I am using Sonata admin bundle to set up the admin. I have Product
admin class and Brand admin class. Now I am able to list both the tables.
When clicked on one of the products, an edit screen comes. What I want now
is, I want to display the corresponding Brand table entries also along
with this screen and also be able to add new brands. Please help me on
this.
I have tried something with sonata_type_admin, but could be of no help.