Content showing up in wrong place

I have a site section that breaks down as follows: Products (top level) - Categories (which the client can update via CMSB) - Brand (client can update) - Individual Products (client can update).

You can see the test pages here: http://mdldoors.stage.esolutionsgroup.ca/products.php. I have two problems:

1. I've only added test data to Fiberglass Textured Doors (http://mdldoors.stage.esolutionsgroup.ca/productsCategories.php?product_category=Fiberglass%20Textured%20Doors) but if you click on any one of the other category link, you see the same Brands listed; e.g. http://mdldoors.stage.esolutionsgroup.ca/productsCategories.php?product_category=Steel%20Doors . This should only show brands that are part of this particular category.

2. Also on this page - http://mdldoors.stage.esolutionsgroup.ca/productsCategories.php?product_category=Fiberglass%20Textured%20Doors - the thumbnails under each logo/summary should only be of the products that are part of that particular brand. I've only added six products: three for the Barrington, two for Barrington Craftsman, and one for Barrington Sierra. As you can see, all six are repeated under each logo/summary, whereas they should be broken down into their respective sections, as described above.

Can anyone tell me how to correct these problems, please? I've attached the two programmed pages.