Cascade Dropdown

Hi gopalk0002
You can achieve this by saving the values to be shown in the second drop-down on the selection of 1st drop-down and show the second one only after the first is selected. 
Make sure to do a null condition if the option is changed in the first one. Something like this.

load(
  local!dropdown1: {1,2,3},
  local!value1,
  local!value2,
  local!dropdown2,
  {
  a!dropdownField(
    label: "Dropdown 1",
    placeholderLabel: "Please select",
    choiceLabels: local!dropdown1,
    choiceValues: local!dropdown1,
    value: local!value1,
    saveInto: {
      local!value1,
      a!save(local!value2,NULL),
      if(local!value1=local!dropdown1[1],a!save(local!dropdown2,{4,5,6}),a!save(local!dropdown2,{7,8,9}))
    }
  ),
  a!dropdownField(
    showWhen: not(rule!APN_isBlank(local!value1)),
    label: "Dropdown 2",
    placeholderLabel: "Please select",
    choiceLabels: local!dropdown2,
    choiceValues: local!dropdown2,
    value: local!value2,
    saveInto: local!value2
 )
})

I like the spirit of this answer. 

Just note that ekanshj - for illustrative purposes, I assume - is loading the drop down values from hard-coded arrays in the SAIL.  This will work fine for the example.  However, in practical application, this can be a chore to maintain.  Typically, a more flexible solution would be to retrieve those values from your reference data repository.

yes Correct. we will retrieve values from data repository.

yes Correct. we will retrieve values from data repository.