I love the ability to just search Hosts & Groups. knowing the host ip and searching for it to find the "host" or the "group" the device is in, really is a great feature.
What would make Termius even better, would be the ability to just search for tags. and by htting the "spacebar" just add the next tag to the search.
I just checked, on the iOS app I am already able to search tags within my connections.
So in that case, having that option with the OS X app is missing then.