Creating clipping masks
The Layers palette lets you create clipping masks to control how artwork on a layer (or in a group) is hidden or revealed. A clipping mask is an object or group of objects whose shape masks artwork below it so that only artwork within the shape is visible.
Now you'll create a clipping mask with the circle shape in the Face layer. You'll group it with the Stripes sublayer so that only the stripes show through the circle shape.
In the Layers palette, drag the Stripes layer up until the insertion bar's double lines are highlighted above the <Path> layer within the Face layer. Release the mouse button when the indicator bar appears.
Drag Stripes layer up above <Path> sublayer within Face layer.For the clipping mask to ...