Helpdesk - issues - allows autorisation


Can you help me. In fact I explain my problem with the module support.
My company manages the patrimony of the customers with the technical techniques (fluids, lighting, fire safety, access control).
At each customer we manage several sites each with several buildings.
Each site contains a site manager, each building contains a building manager and each business line contains a technical manager.

My problem is that when I create a ticket, everyone looks at it and can not be seen by many people.
In the company of service is important to be able to cut these tickets by business techniques.

How can I make it work on the customer portal?

Thank you in advance.