There is a topics page here https://www.hylo.com/groups/skykomish-field-station/topics

And more about topics here https://www.hylo.com/groups/skykomish-field-station/settings/topics

And you can cause topic filters to activate by clicking in the nav menu.

In addition there seems to be a relationship with topics that are used in other Groups! This makes some sense, but how a group defines a topic may change.. and there are some strange effects... like I can't create a topic #Community when there is an existing topic #community... this seems small, but for anal types, it is strangely frustrating to not be able to create consistency within a group.

I would have a single interface that lists topics used IN the group and that allows various topic controls as a privilege. This could include adding or subtracting topics, as well as defining topics.

I'd give some serious thought about cross-group topics, since definitions and contextual use may vary strongly.