Hi Sean, 
Yes, this is a little tricky but certainly doable. Follow these steps.

1) You need to add a second pane for the ES. Press SHIFT+INSERT to add a new instrument to chart. 
2) Add in new pane. Choose the periodicity you want. Set the Footprint Type = Invisible. 
3) With the Footprint Preferences open, click the Footprint Data tab and set the volume filter to > 100 
4) You can size the pane so it is not even visible, but it must be present on the chart so you can tie the FPBS to it. 
5) Add the FPBS and associate it to the new pane you just added. This is done while adding it to the chart and is in the lower left corner.

Let us know if you need any further help. 
Make a great day, 
Trevor

Here is a link to the Discovery Trading Group chart definitions: http://www.discoverytradinggroup.com/archives/870