User permissions

I have build CRM system that contain customer information

Example:
Name, Address, Kontakt info, Projekt .....
I want to different users can only see and edit user informacion defind by Project field.

It work for one user but not for 2 or more on same project

Exempel:
"Name - Adress - Tele - Project"
-Name1, Adress1, Tel.1, Project1
-Name2, Adress2, Tel.2, Project1
-Name3, Adress3, Tel.3, Project1

-Name1, Adress1, Tel.1, Project2
-Name2, Adress2, Tel.2, Project2
-Name3, Adress3, Tel.3, Project2


Users/Data

user1->(all data that contain Project field= Project1)
user2->(all data that contain Project field= Project1 and Project2)
user3->(all data that contain Project field= Project1)
user4->(all data that contain Project field= Project2)


Ideas?