SC Category Table-2 fields created in widget ,how to make dependency between the Parent and child

[Bhavani3]

I have a requirement in widget i created 2 fields -Parent and Child field ,both are choice field, 

If I select parent then child field show only the name which belongs to Parent

How to make dependency between two fields

Below screenshot, In widget  If i select parent as Standard change then child field need to show the Title of those 4 categories