I'm creating a filter system to filter products. It can be based on multiple areas, for example, I have a category 'Shoes' and can filter based on brand, size, type of shoes, etc..

My question is, when I'm filtering the list, the results need to be based on the filter made before? Or based on the original list of products within that category?

For example, if I select brand X and later I select size 9 if there is any other shoes with size 9, even if it's from another brand, should it be displayed? Or should i restrict my filter of size 9 only within the brand X?

I'm creating a filter system to filter products. It can be based on multiple areas, for example, I have a category 'Shoes' and can filter based on brand, size, type of shoes, etc..

My question is, when I'm filtering the list, the results need to be based on the filter made before? Or based on the original list of products within that category?

For example, if I select brand X and later I select size 9 if there is any other shoes with size 9, even if it's from another brand, should it be displayed? Or should i restrict my filter of size 9 only within the brand X?

Edit based on the comments

The filter system starts by showing all the filter options right on page load, so there is nothing else showing up after some selection.

The filter has 2 options: By input, where user type something to search of. By checkbox, where user select 1 or more checkbox from a group of options within a specific filter option (for example: Brand).

This is a simple mockup of my filter, very basic and common.