When conducting a search followed by adding a filter to the search the filter should filter among all search hits. Not just the ones displayed on the current page.
Currently it only filter among the displayed results so if your initial search gets 200 hits that are devided on 4 pages (50 hits on each) adding a filter will only apply to the first 50 hits.
Also, if you have a filter on, it filters on all the tabs that are open not just the one you want filtered. This isn't helpful for us.