From within the dashboard:
To edit the name of a dashboard from within a dashboard,
Click on the menu in the top-right corner of the page and select 'Settings'
In the resulting modal, enter the desired title and click 'Save'
From the dashboards index:
To edit the name of a dashboard from the list of dashboards,
From your navigation panel, go to 'Dashboards' and click on the 3 dots on the far right of the dashboard to access 'Settings
In the resulting modal, enter the desired title and click 'Save'