ake sure that your green compound path is selected and make two copies in front (Control-C > Control-F > Control-F). Select the top copy and move it 1 px down. Reselect both copies made in this step and click the Minus Front button from the Pathfinder panel. Turn the resulting group of shapes into a compound path, make sure that it stays selected, and focus on the Appearance panel. Set the fill color to black, lower the Opacity to 20%, and change the Blending Mode to Soft Light.