Learn to add a "usergroup" or "User" access to a project to view, and do other things with documents in that project that is authorized.

1.    Open the Administrator console 
2.    Navigate to Projects -> and click the plus sign next to the project in question

3.    Click “Security Access” then click “Add” on the top left command bar 
4.    A dialog will appear, under the “General” tab, check the group in question you want to grant access to(note that groups have (group) at the end of their names). 
5.    Click on the “Rights” tab and check boxes for rights that you want the users to have in that project. 
6.    Click “Save” 

Anyone in the group will now have viewing rights to that project.