u/whatinfuck

Hi, I'm trying to teach myself how to weave pandanus leaves/raffia (or other alternatives) and wanted to see if anyone know what this weaving method is? I know its not a 3 braided plait since its flat in comparison to the one in the photo. Any information relating to the process or even sources to see how to recreate this would be appreciated.

(To provide further context, this is an old purse strap made of pandanus leaves from Tonga.)