While changing K2 dropdown option ,I wants to perform some operations with Old value. But in k2 rules we are not able to capture that value. Because K2 has only changed rule.

Example:

Dropdown values : “one” , “two” , “three”

If I change the dropdown value from “one” to “two” then I wants to trigger a button  click event from JavaScript so that will call some K2 rules  once that's done then the dropdown can change to “two”.

Please help.