It is credited to Mark Saunders and Paul Tosey:
Saunders MNK and Tosey P (2012) The Layers of Research Design "Rapport" 30 58-9
You can read their article The Layers of Research Design on Academia.
If you search the Internet there are many versions you can find. I really liked this version by The University of Derby because it has the other offshoots. You can find out more about it on their website.