How to use Brands and Categories together

Hello, I have this problem (I use these two widgets: Filter products by Brand + Product Categories):
When I have filtered the products by a brand, if I try to select also a category to filter the products, the first filter I have choose disappears.
For example, if I filter my products by the brand “Pandora” (brand) and then I try to filter also by “necklaces” (category), I lose the first filter “Pandora” and it shows me the necklaces of all the brands.
Can you help me?