Grafana lets you easily export and import dashboards.
From the Home page of the Region where your dashboard is located, open the dashboard you want to copy and click the Share Dashboard icon at the top right corner.
In the Share pop-up window, select Export tab. Click the 'View JSON' button, then click on 'Copy to Clipboard'.
To import a dashboard, click the + icon in the side menu, and then click Import.
Paste the copied JSON from the first step and click 'Load'. In step 2, click 'Import'.
The new copied dashboard will appear in the appropriate list of available dashboards.
For more details, see the official Grafana export and import documentation.