I think this feature would be a great addition and quite easy to implement.
Right now on the “Browse” page, you have the option to save a search. My idea is a section for “filters,” which would function similarly to saved searches. However, instead of replacing the text in your search bar, it would append it.
So you could start a search in the bar, and then click a filter that adds the text for unsuspended cards in a certain deck, etc. What do you all think?