How To Apply a Dashboard Template
Navigate to the campaign where you'd like to apply the template, and click "Set up Dashboard".
Then, click "Start from a template".
Next, highlight the template that you'd like to apply, and click "Continue".
Finally, type in the name of the dashboard. Click on "Continue" to create your dashboard.
The dashboard will then be populated using the settings and widgets from the template.
Note that dashboard templates can only be applied to an empty dashboard. See here for how to clear your dashboard.