First of all, get_node
accepts a filesystem-like path, and scenes, after they are instanced, are just nodes somewhere in the tree.
This means that you can just do get_node("../../")
to get the parent of the parent node.
But... there is a slight trick. The root node is /root
, and it has the currently-running scene inside it, which means that you can use /root/Game
to get to the node you want.