Just to add to this in case there is any confusion. See http://docs.blesta.com/display/user/SolusVM#SolusVM-ConfigurableOptionsOverview, if you create a configurable option for "nodegroup", you can accomplish this. Inside SolusVM, you would assign your hypervisors/nodes to groups based on location, and your drop down menu would use the value of each node group in SolusVM to reference the location.