eSearch using checkboxes to query results

Hi All -

I came across a webpage that is using Robert's eSearch (2.5) widget with additional functionality to search by amenity. Please see attached image and website:

http://www.gis.dcnr.state.pa.us/maps/index.html

I need to do this exact thing and have been looking online for how to implement, but to no avail. Any one have any leads?

We're running FlexViewer 3.0 and server 10.1.

Many thanks, Meg

Attached Thumbnails