Copy the gray circles shape to the clipboard (Ctrl C).

Select the circles shape and change the fill color to pale blue. Either select the color from the screen palette, or click the small color wheel icon to the immediate left of the screen palette to open the Color Editor where you can enter the precise RGB values.

Select the X and send it to the back (Ctrl B).

Select both the circles shape and the X and from the Arrange pull down menu, select Apply Clip View.

This masks the topmost object (in this case the circles shape) inside the bottom most shape (the X) as you can see on the left.

NOTE You'll notice two keyhole icons when the ClipView object is selected. Clicking the center keyhole icon selects the clipped object and allows you to reposition, scale, or modify the clipped object. Pressing the keyhole icon on the top left selects the container objects which can be modified or repositioned around the clipped objects.