This same type of rhinestone braid or belting, used for a variety of accessories, was popular back in the 1920s and early 1930s. I have come across it used as a belt, or sewn onto a garment itself (on the cuffs for instance), and also as hair accessories or millinery bandeaux. The rhinestones on delicate silver chains like you show could be purchased wholesale by the yard back then and made into various accessories. On your belt, the buckle of choice would have been added by the maker.