Once you have made a node such as an Extruded object, you may like it so much that you want to make more of them. Simplest way is to make an Instance, a Replicant or an duplicate.
An Instance is a node that takes the mesh of the original and lets you move it and rotate it. When you edit the control parameters of an Instance, the original and all other Instances will be edited as well. To create an Instance select an object in the SceneView and then hit the keystrokes for duplicate, ⌘D. The new Instance is selected and if you drag the translation handle, you can reposition your new instance.