Hi, Dianne.
I hate to say this, because I'm a long-time user of NovaMind mind mapping software. I love the program and find it endlessly useful and entertaining. However…
The diagram you're describing sounds like a flow chart. NovaMind is not the ideal software to use for creating that type of graph. You'd be better off with something like OmniGraffle. While the latter can be used for mind mapping, also, NovaMind beats it a thousand ways to Sunday in that department. Where OmniGraffle is superior is in creating flow charts, organizational diagrams, genealogical charts, etc.
Let me show you the difference.
The closest I could come to building what you want with NovaMind:

Creating this sort of image took a little fiddling around. The diagram you see next, using OmniGraffle, took only seconds.

You might consider using OmniGraffle or another graphics program to build the kind of geometrical, hierarchical, linked diagram you described.
Good luck!