The simple shape is a mask, so input in it doesn't work. Use the SSS to displace something, so pull its output to the displacement tab of a surface shader. Default is 1, but set it 100 and you'll see something happening. Make the SSS a soft circle, say 90% with a bevel or smooth step. You can also add a PF between the SSS and surface shader, as an in between mask. Adjust the colors to your needs; black is no displacement, white is 100%, so you could set a 0.7 grey color in the low color, and adjust sizes to maybe 10/200/0.1 for a 100m diameter circle, then set color roughness to something less than 1, or you'll get ugly spikes. Experiment.
The simple shape can also be used directly to displace, but I never actually use that.