Clicking on the gear icon (Details) will bring up a details view similar to the normal Assignment Details view.

Clicking on one of the colour tags in the lower left corner will bring up every assignment of that state to the right. From here you can take action to approve all of the blues (turning them green), cancel all of the blues (turning them red), or cancelling the shifts entirely (turning them black). You can also manage any of the individual assignments as normal from the Scheduler.