CheckLookupEditorAttribute.CascadeField property
namespace: Serenity.ComponentModel assembly: Serenity.Net.Core
Cascade filtering field (items will be filtered on this key, e.g. CountryID) Make sure you have [LookupInclude] attribute on this field of lookup row, otherwise you'll have empty results as this field won't be available client side.
public object CascadeField { get; set; }