This exercise combines Twisting arm circles with Deep archer squat ; refer to these two exercises for the form details.
Perform a Twisting arm circles and when one arm goes down to the side, bend the opposite leg.
The arms movement should stop abruptly when you reach the bottom of the Deep archer squat , with the bottom arm pointing towards the foot of the straight leg, and the other arm pointing upward in the opposite direction.
Then reverse the arms movement to do the other side and keep alternating.