A simple snippet to paste multiples of the copied node underneath the selected nodes.

To use just copy the node you want (ctrl-c). Select the nodes on which you want to paste the copies and run the script. Simples!

#paste to multiple selection
selected = nuke.selectedNodes()

for eachNode in selected:
    n = nuke.toNode(str(eachNode.name()))
    n.knob("selected").setValue(True)
    nuke.nodePaste("%clipboard%")