To invite a Company Manager - Click on the dashboard button at the top left - Click Preferences > Company Managers > Invite. A Company Manager will have access to all company projects along with the ability to invite other Company managers.
To invite a Project Manager to a Project – Click on the dashboard button at the top left - open the desired Project, then Preferences > Project Managers > Invite. A Project Manager will have access only to the project to which they have been invited.