Note: The number of Custom Dashboards you can create depends on your plan. You can create one custom dashboard on the Essential plan, three custom dashboards on the Premium plan, and unlimited custom dashboards on the Enterprise plan.
Web:
Go to Reporting tab
Click Custom Dashboards
From list of Custom Dashboards, select dashboard to open
In top right corner of graph, click 3 dots (⋮)
Click Duplicate
Add title
click Save