To add the stacked protocol trend view to a dashboard you must do the following:
1. Create a new dashboard or edit an existing dashboard
2. Choose "Select Context" on the left

3. Change the context type to interface and make sure oyu choose an interface where "Flow" is on

4. When you click "Ok" that sets the context
5. Under the "IP Flow" section choose "Stacked Protocol Trend" (or any other view you wish)

6. Drag it over to the right and save it.
The view will now be added to your dashboard