Allow user to see certains tickets

Hi,

I actually have an help topic personnal and inside there is a drop-down list with different choices (marketing, communication, sports etc....). I would like to allow a user (and not an agent) who is registered can see and manage tickets of his job. From example, people who works in communication can see only this category tickets.
The goal is to define one user per category and allow this user to see the corresponding tickets.

Thanks a lot.