In Teams, it’s easy to see all the conversations (message threads within a channel) and messages that you’re a part of at a glance.
At the top of the left sidebar, click the Activity icon. This opens the Feed pane to the right. To the right of the Feed pane title bar, right-click the Filter icon (three horizontal lines in a funnel shape) and select @ Mentions from the menu that opens. (Or type /mentions into the search bar at the top of the Teams app.) Conversations that you’re a member of, and messages that you’re tagged in, will be listed in the Feed pane.