Here’s what your function would look like:
You just drag your character’s mesh component to the graph and drag off its pin and search for “get socket location.” Bones and sockets are the same in this context.
Then plug the returned vector into the return value of the output node for your new function.
Finally, “get socket location” requires a socket name. If you’re using the default ue4 mannequin then the head bone’s name is just “head.” I’m pretty sure it’s case-sensitive, so be careful.
If you’re using a different skeleton, open up the skeletal mesh and go to the skeleton tab and look for the head bone. Right-click it and copy the bone name.
Add that bone name to the “get socket location” node and your function is complete! I recommend making the function pure to remove the execution pins.