You can view all your metrics aggregated to locations of your choice and accessible to you from the Dashboard title bar locations selector.
Click on the title in the dashboard view. This would take you to the locations screen which shows all locations you have access to.
Select locations that you would like to view metrics for. You can select them by zone, search for a location or select all. Click on back link to save your selection and go back to the dashboard.
The dashboard now displays the various metrics across the selected locations.