Admin Management access will give you the ability to add Admins and change permission level(s) of existing Admins. Access to this feature will be limited to the owners of an organization.
To access the Admin Management module go to the "Settings" tab and click "Admin Management"
Click the pencil next to the specific admin's name you would like to add an additional project to.
This will open up a module to edit their access their access. Click "Add Project" in the lower corner to add projects for the admin.
Select the project you would like to add from the drop down. Click "Add +" then then "Approve and Perform Action"
The newly added project will appear at the bottom of the project access list.