How to run development sprint and design sprints in parallel

[Dianne Castellanos]

I am working on ongoing projects that need parallel sprints. We have a development sprint and at the same time a design sprint that are tasks and sub tasks. Is there a way I can add only the tasks of the stories into a Sprint? I am trying to run them on the same board however it will not let me add only the task, its asking for the story as well. 

Does anyone have a good way to have both of these sprints going without making 2 separate boards? 

[Dc1crew]

Has the drag and drop function been rehabilitated? We are unable to drop pictures