You can define relation between Forms Fields - decide which fields should be reloaded when value of the selected field was changed.

​

Fields selected in refresh parameters list will be reload after change of the value of the current field. Lookups used in the selected parameters will be recalculated to match current form fields values. The functionality can be used to build cascade field relations.

Note: If selected 'Asynchronous Form' please use lookups to Workflow Data -> Current Form -> Form Fields to dynamically get current values of other fields on form, when updating current field.

Example: In Refresh Parameter section for field 'Category' 'Items' parameter is selected. 'Items' field value and title depend on 'Category' parameter value. After change of 'Category' field 'Items' field is recalculated and reloaded to mach current selection. Also 'Selected item' field depends on 'Items' field value and is selected in its 'Refresh Parameter' section.

Additionally check our walkthrough how to use Form fields interaction provided example.