From the Jobs tab, click on the Job name, at the top click the Users tab, then click the "Assign Users" button to select users to add to the job.
Using the check boxes on the left, select any users that you want added. Use the upper most check box to select all available users.
Use the search bar to search for users by name.
Use the All Roles drop down menu to filter users based on their role (dispatcher, supervisor, etc).
Use the Select Group drop down menu to filter users based on their group.
Click the "Assign Users" button to save your selections and add them to the job. Any users added can now view and manage this job (based on their permissions).