Isotope: Display More Filters When A Filter Is Selected

I’m trying to make my Isotope filter list more user friendly by hiding filters until something is selected.

Here is a JSFiddle:

I had trouble getting the Isotope to work in the JSFIddle, but hopefully I can get still get the needed help.

In the Fiddle, there is a thick green line. Below that line are the filter options I would like to be hidden unless a “Body Part” is selected.

So if the filters below the green line are hidden, and a user selects “Chest” under Body Part, the “Chest” filters will fade in then the user can select Upper,Middle, or Lower.

I haven’t seen this covered in the Isotope documentation how could I do this?