The Favourites button on the Navigation bar, allows you to view a list of pages you have bookmarked and the last five pages you have visited.
Currently there is a known issue, in which a community stays in the Favourites list after a user has left the community. For more information, see this FAQ: Why is a community still in my Favourites after I have left?.
To view the last five pages you have visited, hover over Recently visited.
Adding content to the Favourites list
To add an item of content to the Favourites list, click the Favourites button.