It says it does represent double majors, but probably not in any useful capacity that you were looking for: "Those with double-majors have two arcs on the left

It says it does represent double majors, but probably not in any useful capacity that you were looking for: "Those with double-majors have two arcs on the left (one from each of their majors, each arc of 1/2 thickness) that combine into one resulting career choice."