Windows 7 Network Group A, Group B and Group C

[Siong Li]

Group A = few computers
Group B = few computers
Group C = few computers

What i want is:

Group A can connect to both Group B and Group C.
BUT
Group B cannot connect to both Group A and Group C.
Also BUT
Group C cannot connect to both Group A and Group B.

Its like a pyramid if you know what im saying.
How do i set the IP ?
Im using Windows 7 ...

Your help is greatly appreciated!