Character rotation with blendspace

I have a blend space with 3 anims:
TurnLeft, Idle, TurnRight.
Values are from -90 to 90.
So, the [roblem is that character should rotate only when i press move keys.
Camera is free, and it’s YAW is from -180 to 180 and when camera’s yaw is 0 actor’s yaw is -90.
Is there any ways to compute difference between cam and actor position and play animation using blendspace?