It appears that this guide is for strips only. It would not help once you are sewing the pieces together. It looks like there is a plastic sleeve that you feed the strips of fabric into...
I enlarged the picture on my screen and it looks as though the widest fabric you can run through the guide is 2-3 inches. This would be great for sewing two pieces together, but I don't see where you could add on additional strips on using this tool.....
Maybe if someone comes across a clearer/more enlarged picture of this guide and instructions.....