For Server 2008
Open Server manager
Expand roles
Expand Active Directory Domain Services
expand the domain and follow Part B below.
For Server 2012
Click on Tools and select Active Directory Users and Computers
follow Part B below
Generally for both
click on start
Click on Administrative tool
click on Active Directory Users and Computers
Part B
Select the OU
Click on the User group and on the name of each user,
Select the Properties box
Select Organization,
Here you can find the job titles.
Note: This can be performed as well using PowerShell commands