This post-function is obsolete. While you may continue using this post function, which will not be removed from JMWE, we recommend you use the more powerful Set issue fields instead for new automations.
To add 'Set field value of linked issues' post-function to a transition :
Click Edit for the workflow that has the transition you wish to add the post-function on.
In the Workflow Designer, select the transition.
Click on Post Functions in the properties panel.
Click on Addpost function.
Select Set field value of linked issues from the list of post-functions.
Click on Add to add the post-function on the transition.
Select the field from the Field drop-down.
Select the link type from the Issue Link Type drop-down.
When you add this post-function to a transition and trigger the transition, the add-on sets the specified value(s) on the selected field of all issues linked to the current issue through the selected link type. The value can be provided either as text (with optional Nunjucks annotations) or as a JSON value.
In the case of text, it can be a simple string (for text typed fields), the string representation of a number, date or boolean value, or the string representation of a complex value, such as a Version name, a username, a Project key, etc. Multiple values can be separated by commas. You can also use Nunjucks annotations to insert issue, linked issue, transition and current user information into Value, using the 'issue', 'linkedIssue', 'transition' and 'currentUser' variables, respectively.
In the case of a JSON value, which requires the option Treat value as JSON (explained below), it can be a String, a Number, a Boolean or an Object. It can also be an array of such values.
Copy only if not set: Sets the value of the selected field on all linked issues only if the field is empty on the linked issues.
Create missing value(s): Allows creating any missing Component/s or Version/s while setting or copying a field that expects Versions or Components. Note this is applicable for version and component fields.
Ignore empty value: Will not set (clear) the selected field of linked issue(s), if Value is empty or null.
Add value(s) to the linked issue: Appends the specified value(s) to the selected field of all the linked issues. This is applicable only to multi-valued fields.
Send notifications: Jira sends notifications for the change in the selected field value on the linked issue(s). You can control the default value of the "Send notifications" option in the Configuration page under JMWE administration. Click here for more information.