I'm making a long tunnel that will have structural supports, wires, and other little odds and ends all the way through it. It will be the same stuff over and over again. Rather than have to do a motion path or to figure out the exact rotation and translates to duplicate each individual object 15 times each to place each one down the tunnel (which is a curved tunnel by the way), it would be easier to simply make an instanced group, duplicate it down the tunnel, then never have to worry about duplicating the objects within repeatedly. I could then create new objects within the group and position them as needed only once and they would automatically be instanced in the instanced groups down the tunnel.
As far as I'm aware, no. You see, an instance is basically two transform nodes that share the same shape node. A group node is a transform node. So you can't have two "group" transform node that share child transform nodes... then they would be in the same place. I doubt that makes sense, but essentially instancing only works at the shape node level.
You can probably accomplish the result you want with scripting, but I'm not sure if there's a straightforward approach.
Ah, okay, I'm understanding this differently now.
What happens is the objects are actually sharing shape nodes AND transform nodes. I didn't see how two objects in two DIFFERENT positions (e.g. translate) could have the SAME transform node, and so have all the same translate values. BUT, each value in the transform node is RELATIVE to the parent, so of course if the transform of the group is different, that will influence the children.
So I was wrong Darkware, thanks for enlightening me Dave. What this means is if you change the position of any of the children, each of the instances will also change position because they share the transform node. Neato.