Vintage 80s off the shoulder Midi Shift Dress

Super cute and interesting shift dress. There is a seam in the back at the hips that allows the dress to blouse over the skirt. There are three buttons (one at the center and one on each side of the dress at hips) and I have no idea what they are for. Loose polyester, not lined. Dress Measurements Length: 43” Bust: 36” flat Waist: 28” flat Hips: 22” flat