Cant share groups and groups are missing

I am set up as a Company Administrator, however, when we first started using this product someone else was also set up as a Company Administrator so not one person was an administrator in case of holiday etc.  Well, we have noticed that when a group has been created by the one Administrator it is not visible for the other Administrator. Also, I can't seem to make groups shared as I did not create them!

How is this resolved as the other Administrator has since left the company? (I have since seen the QA about a master account to stop such things)