You may have noticed that, although your colleague is connected to the same company profile that you are, they are seeing different jobs, on campus interviews, applicants, etc. that you are. This is due to our Network Management feature, which you can read in more detail about here.
In short, institution approvals are company based (meaning if an institution approves your request to connect with them, that approval will carry over for every user connected to your company's profile), however, each user connected to the company profile will create their own separate list of institutions to have on their own individual Favourite School's List. You will only see information of the institutions you have added to your Favourites List. You can add an institution to your Favourite's list by following the guide here.
While there's not a way to mass-add all approved institutions to a user's account, all users do have the ability to toggle between seeing only information for the institutions on their Core Schools List and all institutions at which the company is approved. Again, this does not add the approved institutions to their Core Institutions List, but does enable them to see jobs, applicants, etc. of all institutions the company is approved at, which would otherwise be hidden. Here's steps on how to do this.