I was kind of hoping someone else would have had an epiphany and posted some thoughts here, since I too am not sure of the diagram.
I completed the text part of the question last night but don't have any bright ideas about the diagram.
If the question asked for a table you could show where the overlap is between benefits and stages. I guess I will have to try and be creative tonight in completing the question. Maybe a sort of table but in picture format of the stages and associated benefits in a linear fashion (if that makes any sense) moving from one to the next?