Granting or removing access to the project is similar to doing so using Portfolio/Setup/Security except that it only applies to this project and to specific users.
Users Tree
This tree displays all of the defined user groups. Expand a group to see all of its active members.
This tree displays all of the user groups which have at least one member with access to the project. The icon next to the user indicates their level of access. In the screenshot above, for example, Carroll Nash has access to the program this project belongs to and thereby has access to this project. Karen Watson has system level access - access to this project as well as all others in the system. User "Sample" does not currently have access. To grant her access, left-click on Sample and select "Grant Access". The icon then turns blue, indicating that Sample user has been granted access to this project. right-click on Sample again and select "Remove Access" to reverse the permission.
Only users who have not yet been granted permission to this project can be given access in this tab and only users granted access at this level can have their access removed here.