The Favorite feature allows you to mark Aggregations, Dashboards, and Diagrams that you work on frequently for quick access from the home page.

To mark one of these entities as a favorite, choose that entity from the list on the appropriate page, then check the Favorite option next to the dropdown:

Once that's done, you should get a notification that the change was saved. After that, the entity will appear in the Favorites section of the home page, where you can click it to go straight to editing that entity.