Favorites
Favorited dashboards display as a drop-down list under Dashboards in the main top navigation menu.
Favorite a Dashboard
Navigate to the Dashboard menu (or Dashboard > Manage Dashboards). A list of all the dashboards available in your tenant appears.
Click next to a dashboard to favorite it.
Unfavorite a Dashboard
Repeat the above process and click 
to unfavorite the dashboard. This removes the dashboard from your quick drop-down list in the top navigation menu.