/cgl/ - Cosplay & EGL

I'm not quite sure what to do for the white bit here, my original plan was to just use bias tape to trim the whole outside of the tunic here, but it looks like in the four sections of the tunic that are separated, the white bit is closed and then cuts in half to trim the bottom part of the fabric? I'm not quite sure how to go about doing that... I know it looks all zipper-y here but it should be solid and fabric-looking I believe