Step 1: Create a list called "Active" and Create one list item in it as "Active".
Step 2: Create a property in your "Graders Name" list as Active and format it as the above created list. Then select active to the list items that are active.
Step 3: Create a line item in your module and format it as Active list. Then either select Active from the drop down or write a formula in the line item. After you do this now the line item that is formatted as "Graders name" list will have dependent drop down based on the above line item.
Now you will be able to see only the Graders name that you have given as active in in the property of the list. I gave 1,3 and 4 as active so i am able to see only those in my drop down.
Hope this would be helpful to reduce the dropdown list of a column.
@kavinkumar Many thanks for this, it is a great explanation!
I tried it for a similar requirement - in that I have a "Graders" type list which is hierarchical and I was hoping to use this to select only the leaf items, however the ancestral items were still included in the list and not just the leaf items. This seemed to me to return the same items as a subset did (in this example "Active" subset). I cannot think of an advantage of using your method above to using Subsets in a list.