Controlling vert. axis in blendspace with mouse yaw input?

I have a 2d blendspace with a jog->sprint anim in the horiz axis, and a left->right lean in the vertical axis. I want the value of the vertical axis to be determined by the mouse yaw/left-right input.

I tried calling the rotation and setting it to a global variable, like they do for velocty/speed in the anim BP event graph, but couldnt get any results.

How is this done?