In order to give access to an employee to the Dashboards menu please follow the steps below:
Go to the employee's profile.
Click Security and then Permissions.
Click Edit Employee Permissions.
Search for Config - Dashboard and click the eye icon to enable it.
Add additional edit, add or delete permissions if needed by enabling the pencil, plus or recycle bin icons.
Save.
Once the above has been completed:
Ask the employee to go to Setup and click Settings.
The Dashboards menu will no longer be greyed out.