This should be able to give you some further insight into what you're trying to achieve;
The main thing I would say is there really isn't much harm in just leaving it on the User model. If there isn't an explicit need to move it, you probably shouldn't. Other developers who get involved might not think to look at the Employees table, and, what happens when you need to add to or adjust your codebase in the future?
Keeping it on the User model makes more sense because what if suddenly the scope of your project changes, and now you also need to add Employers, Managers, Administrators, or something else? Suddenly, your whole user system breaks apart.
However, if you keep it locked to your User model, you can handle all user elements in an easy place, and use either roles, or even relationships to other models to handle the various elements you're planning to work on.