In Version 3.0.3, Joget added support for Dynamic Cascading for Select Box/Radio button/Checkbox. It allowed these fields to dynamically load available options based on the other field value. How this feature work is it load all the available options at once then show/hide it when the value of controlling field is change. Please refer to Dynamic Cascading Drop-Down List to understand about this feature.
Come to Version 4.0.0 release, Joget enhanced this feature to support Ajax loading of cascade options. This feature help to improve the performance when you have a huge number of options and you only want a few options that related to your controlling field to be loaded and shown.
To turn AJAX loading on, you only need one extra step from Dynamic Cascading Drop-Down List tutorial. Check on the checkbox of "Use AJAX for cascade options?" when you are configuring the Options Binder. This property option is currently available on BeanShell Options Binder, Default Form Options Binder and User Options Binder. 