So, I assume that you want to have the ability to filter discussions by multiple tags. That's actually quite nice idea, but I think that it's not on the scope of developers yet. On the bright side, I think that when the search will be revamped in upcomming Flarum releases, this is something they could take in account and look at.
P. S.: Despite there being an English version below the original text, it's still recommended to use English, as this is English-only forum.
