To join an additional team in your Microsoft Teams organization, click "Join or create a team" at the bottom of your left sidebar. From there, select the team you'd like to join.
Using Slack? See Joining Matter Slack channels.
For an overview of the whole feature, read the Matter setup and rollout guide for Slack and Microsoft Teams. Related articles: How to uninstall Matter from Microsoft Teams and Automatically add users to Matter in Microsoft Teams.

