Hello Mangala,
It's great to hear from you again. I can see how having the option to track the deduction payroll item by job or classes would be useful to you as they can help with narrowing down information in reports and seeing details in certain ways.
You're right, a few of the payroll item choices, such as Additions, have that checkbox where you can choose to Track Expenses by Job or Class. At this time, there isn't a way to configure that sort of setting for Deduction payroll items.
If you're hoping to see information a certain way in your reports, I recommend checking out the Customize item reports and Customize payroll and employee reports articles to learn different ways to see your payroll information.
I recommend in this case is submitting feedback about what you're looking for with setting up the deduction payroll item. Doing this lets us know the features you're looking for in the program, which are taken into consideration by the product development team for future updates. Many of the features you see today once started as suggestions from users like you. Leaving feedback is super simple: go to the Help menu and choose Send Feedback Online. Follow the options and your comments will be on their way.
Give me a shout if you have further questions. I'm here to help however I can.