It is possible to give an extra option into the accordeon to allow users to search within the hidden areas. Although it might be confusing. I will talk to my designer friends about it. I'm worried not only for the performance but also for the usecase. Not sure how confusing it might be when user entered "Stuff" in the search area and then several accordeon tabs just disappeared leaving only few on a screen. It is hard to grasp on what is going on the screen.