Cut 14 2-inch-diameter circles from the contrasting color of felt.
Fold in sides of the circles and secure with two rows of stitching.
Cut each circle in half between the rows of stitching. Align half circles along the edge of a tieback piece; pin, then baste in place. Layer the second tieback piece on top of the first; pin, then topstitch. Cut a buttonhole in one end.
Make a covered button according to package directions, attach to the tieback, and button tieback around the curtain.