How to create sub-task based on custom field value

Overview

This article explains how to create a sub-task using the app, Create on Transition's Create sub-task post function, based on a custom field value on the parent issue.

Instructions

Add a post-function in the workflow associated with the parent issue. To create the post function,

1. Log into Jira as an Administrator and click  > Issues.
2. Under the Workflows section, select the intended workflow and click the Edit link.
3. Select the transition to which you wish to add the post-function. Select the Post Functions option as shown below:
   
4. Click the Add Post Function link and select Create Sub-task from the available options.
5. Provide the below post function along with the Conditions:
       a) Provide the custom field id in the Condition value and their values in the Regex pattern as shown: 
   
6. Click Update and publish the workflow.
7. Once the post function is created for the transition based on field values for custom fields, Release and Release instance, you may notice that a sub-task is created for the issue.