When you load a repository, the first dashboard you see is your default dashboard. A dashboard with a green line located at the top of its tab signifies your default dashboard.
To set a dashboard as the default, right click on the tab of the dashboard and select Set As Default from the pop-up menu.
The dashboard is now set as default and will have a green line located at the top of its tab.
From this point forward, it will be the first dashboard you see upon logging in.