When you want to go to the last webpage you visited, you hit back button on your browser. You can do the same thing in Microsoft Teams. The back and forward buttons in the top left corner bring you to the recent locations you have visited within Teams.
Hover over the back arrow and you'll see the last 10 locations you visited. Select from these recent sites or click the arrows to move back and forth between visited Teams and Channels.
https://competenz.freshservice.com/support/solutions/articles/5000082945