set Lens filters as mutually exclusive

Hello,
when I switch a filter to better refine a search into a Unity lense - be it by app category, file size, or the 18 music genres - the change between filter is not mutually exclusive, but accumulative.
This behaviour is not convenient at all, forcing the user to deselect the filter previously in use to gather better search data.
Adding search results when selecting different filters is even conceptually wrong when the goal of filter is to exclude objects: this is absolutely a design bug.
Designers should correct this behaviour, so when we select, say, Games, or 100kb, or Rock, Dash space, which is limited, is not polluted by other no more useful data.

Thanks for your attention,
alex

ps. I guess if The Replacements are filed under Punk or Rock..