CMS Block to list products grouped by subcategory

I need a cms Block that displays all products under a atribute page (ex. brand) gruped by subcategories. Example i have: product1. Brand "coca" Category - Subcategory 2 product2. Brand "coca" Category - Subcategory 2 product3. Brand "coca" Category - Subcategory 1 I want to show in: http://www.website.com/by-atribute/brand=coca CMS Block that list the products with brand "coca" grouping they by its subcategory. Subcategory 1 Product3 Subcategory 2 Product1 Product2