From a couple that sailed around the world and this item was purchased at an island they visited.  She said each island had their own pattern and these items are belts/wraps/scarfs.  

Per my google search:  This appears to be a handwoven Indonesian textile featuring a geometric pattern in black, gold, and green. These textiles are traditionally made using a resist-dyeing technique where threads are dyed before weaving to create intricate designs. They are often made using natural fibers and dyes, with variations in color and pattern depending on the region and artisan. Such pieces can be used as decorative elements in homes, as clothing, or as ceremonial cloths