I have a requirement to use dependent Drop Down and autofill based on the selection of previous value, along with to backfill the dropdowns based on the value selected from other dropdown. For example, I have School list based on city, so it narrows down the schools by city and I have completed this part, but if you don’t know the city and know the school, I want to be able to select the school and have the city automatically back fill.

Currently I did implemented it using many if else block, but this does not seems to be efficient.

is there a good and efficient way to do this?