Add an Update Issues post function to the appropriate workflow transition 

Assumes you have installed the Update on Transition for Jira app

Create a JQL query that retrieves the issues that need to be updated

• Test the JQL in the Issue Navigator first.

• If you are using substitution variables, make sure values with blanks are quoted.

• Use an ORDER BY clause if it is important to find only the first issue satisfying the query.

labels = cw order by key

Put the working JQL query in the JQL Query field

Add the JQL result to the Issue to update field

• Determine if you want all issues matching the JQL or just the first one.

• Select the appropriate replacement JQL based replacement variable.

• %jql_result_list% - comma-separated list of issue keys matching query

• %jql_result_1% - first issue matching the query

Set fields to be updated based on absolute values or Substitution variables

If necessary, add conditions

See Use pattern matching conditioning

Save the post function

Run a test scenario

• Use Get problem determination information to debug your scenario if necessary.

• JQL errors will be logged. Note: This is the most common cause for not getting the expected updates.

• Remember, the JQL query runs under the user's permission unless you are using Acting user support.