Based on feedback from customers, we have added a new feature to dashboards. You can now export to CSV by clicking a button at the top-right of the view in the dashboard:
Exporting from a dashboard will take into account the currently selected slicer. For example, in the screenshot above, clicking the highlighted button will export the aging report, filtered on "Assignment Group = Database" and "Assigned to = All".
For more information, refer to the Explore Analytics wiki article regarding dashboards.