It is highly recommended to follow this guide to copy a dashboard before attempting to customize anything relating to an existing dashboard so you don't apply changes to a dashboard other users rely on. After copying a dashboard, any changes you make will not affect other users. Note: You can only duplicate a dashboard that you are already the owner of.
Copy a Dashboard
Input "Dashboard" in the filter navigator.
Under Self-Service, click the Dashboards application.
Select and apply the dashboard to be copied. In this example, we use a test dashboard.
Click the menu button in the upper left hand corner of the content frame, and select Duplicate dashboard.
A copy of your current dashboard will be created with the name Copy of <Dashboard name>.
To change the name of the dashboard, click the menu icon again, and select Dashboard properties.
Change the Name field.
Click Update.
For more in-depth guides to editing your now copied dashboard, check out Edit a Dashboard.