How can we create function in case of Postman flows

I have to decode the jwt to fetch the details and use it in subsequent requests. In the collection I created a function to perform this action and was setting the environment variable to use in requests. Now the option available are durable and variables which only set the values from response object. Is there any way to perform some operation on the response object values before using them as variable in the next request.

You gonna have to be more specific on what “operation” you want to do