In this page, accessible through the Employee Management menu, you can see the employment history of the employees.
Here you can also edit the employee's employment history by clicking on the button at the top right part of the screen:
After clicking on "Edit" you'll be redirected to a new page similar to the one below:
You can add as many previous employers as you want, and also remove as many as you want until you don't have a single one left. After finishing your edits, simply click "Save" at the top right of your screen to save, or if you don't want to make any changes, simply click "Cancel" or the back button at the top left of your screen.