Can't see your image, so I'm just taking a guess at your problem. Unstabilize requires input from a Stabilize behavior, if you don't have one on the clip you reference, nothing will happen. For example you could run Stabilize on one clip then turn it off. Apply Unstabilize to another layer and reference the Stabilize behavior from the first clip.
Other options are to use the Wiggle or Random behaviors and apply them to the chanels you need (Postion,Scale, Rotation) to get jittery motion. The advantage of Unstabilize is that if you have Postion, Scale and Rotation selected in the Stabilize behavior, it's simple setup, and is a better way to match the background in a shot. Using the other behaviors is good for some general random motion.