By default a complete list of users available for Project Kaiser Administrator only. However, in most cases for Administrator it is enough to add manager only to a newly created project. After that manager is able to add users to project by himself.
Here is an example.
1. Administrator creates "Sales Department" and adds users to this project:
2. Administrator creates second project "Department Of Marketing" and adds John as Manager:
3. As John is now manager in both projects, he is able to add Victor and Kate from "Sales Department" to "Department of Marketing" team too: