Motion controllers as bones

I have a set-up that takes motion controllers’ relative transform and uses it to transform a specific third person character’s bone. I am using a Vive and BPs.

Now, lets say I do twist my head to a side, how do I determine whether my virtual character’s body should turn too? Both HMD’s and controllers’ transforms should be used to determine so, I guess? Same about hands, how do I determine what bone should move and/or rotate?