It is possible to co-host an event with an external business entity and give them access to view event statistics.
To do this first you need to couple of things:
Create a Business Profile with all required or necessary information.
Create an Event and configure as you find appropriate
Within Event settings you'll find configuration for "Select Host Company", from there type in Business Profile name that you just created.
In this way, we can provide limited access to the event via the portal. Setup a directory profile and assign a CRM record to access. Now make sure to assign to directory profile on the event.
Then if and when they login at "members.client.domain/account/menu", it will display the event, where they can bring in any necessary changes without have to "login" to back end Control Panel.