Are we talking tickets or requests?
If your user is looking to see all tickets of all types, you can create a report for him that filters on all of his accounts. You can then publish this report to a desktop or make it visible to just him in the Ticketing app.
If he's looking to see just requests from the service catalog, there is a page in the client portal that will allow him to see ticket requests. If he has the " View all requests belonging to assigned accts/depts" permission on his security role, he will
be able to enable a checkbox on the "Ticket Requests" page in the Service Catalog that will allow him to view all requests for his department.
I hope this helps!