Note: Custom Properties are subject to access. Only those who have the appropriate permissions will be able to create the custom properties.
To create an Employee's custom property, go to Employee and then click on 'Custom Properties.' This will enable selected users to create custom properties it will be available for all employees of your site.
Create a desired 'Label' for example 'Address.' Then set the 'Control'. It would be a 'Checkbox' for this example. Then click 'Save'.
Below is how the controls will look for Custom Properties.
