Take this instrument and colorize the lateral sides of the circle. The color must coincide with that one of the background.

Pass to create the menu. First we should choose the instrument with a Radius of 10 px and represent 3 stripes.

Set next adjustments for all of them in the Blending Options.

We need to draw a circle now with the following instrument . Then click on the Alt button and draw another circle inside the first one.

Set the adjustments for the circle in the Blending Options.