Hey Stephanie, I think you're ALMOST there. If you take a look at the WSAPI doc, you might be able to find the field references you're looking for.
I think if you're scoped to Tasks using the Task Board app, if you want to traverse up to the User Story's ScheduleState then you have to do something like:
WorkProduct.ScheduleState > "In-Progress"
Give that a shot and let us know how it goes!