Issues with Creating Cascading Combo

Hello,

I'm currently trying to create a cascading combo based off the guide found here:

http://help.bizagi.com/bpm-suite/en/index.html?cascading_combo.htm

I've built out the data model to include Country and Capital. The guide above states that when I drag in the lowest level control (i.e. Capital in this case) into the forms function, Bizagi will automatically drop in the rest (i.e. Country). However, when I drop in the Capital control, Bizagi only imports the one Capital drop down. When I manually add in the Country as well, the two operate independently of one another. I've inserted the values into both the Country and Capital entities and referenced the Country in the Capital values. I've included screenshots of the data model and the form controls. Can anyone tell me what I may be doing wrong?