I have different projects with tasks. And I have configured a filter to see only issues with a given label, as we have defined different teams in the organization and see the backlogs with this given label.
When I create a scrum "Board from an existing project" and go to "active sprint" I can see the subtasks of the issues. Ie: in the following screenshot I can see the issues from LOG project in the current sprint (only for this project). I can see (and play with) the subtasks.

But, if I go to the scrum "Board from an existing Saved Filter" to see the "A Team" label issues in the active sprint... I can't visualize the subtasks but only the issues: 
How can I manage this?