The access rights I have provided are just three people, but all the employees of the same company are listed as the project team, but that is not so.
Am I doing something wrong in the setup?
It's not clear what you want, however I can say that you can either choose all members (of a company) to participate in a project, or you can choose them individually.
The key piece of information that might help is that the FIRST company you define is assumed to have special privileges, i.e., access to all projects. Therefore, if you don't want this, then create a special company only for admins which will be the first company, and add your team to the second company.
Ah, that was it Paul. I had the Company selected AND members selected. I thought the company selection was the responsible company, not that all the members of that company would also become project members.
I found that if I do not select a company and only choose three of the members, those members are the only ones listed on the project. However, if I choose a company, than all members of the choosen company are members of the project as well.