Default start date to sprint start

[Richard Way]

I have the plan settings set to use the sprint start date if no start date is set. And I added the Sprint to the list view to verify it was pulling correctly. The sprint shows "EXT" and that it's not in the plan. 

The challenge though is that the Plan covers multiple teams, each team has their own board, some of those boards cover multiple projects. 

Is there a way to set the scope to multiple boards and then set a locked filter to limit the plan to just the appropriate Initiatives?