This script will bubble nodes up the tree quickly and easily. (the left-side inputs only). Bind it to a key and hover over a node and hit the key. If you are on Houdini 6, its easy to modify the script to not use the mousepath() expression and you can add it to the OPmenu commands very easily.
Bind it like this:
alias F7 source bubble_up_this_node.cmd
alias F8 source bubble_up_this_node.cmd down