Yes,
You can have create a connection on your second hypertrend like the one shown below:
Hypertrend2.ActiveGroup = Hypertrend1.Active Group.
This connection pretty much sais that the active group on the second hypertrend will be the same as the one selected on the first hypertrend (just remember that ActiveGroup is defined by a number and not a name).
Also, you can have a Pot that selects the multiple actvie groups on both hypertrends. The connections on the hypertrend objects would look like this:
hypertrend1.activegroup = Pot1
hypertrned2.activegroup = Pot1
I hope this helps.
VG