Use case
Return the keys of the sub-tasks that do not have original estimate or story points estimate.
Expression
Create and configure a Smart field using this expression in Jira expression mode:
issue.subtasks.filter(s => s?.originalEstimate == null && s?.customfield_nnnnn == null).map(i => i.key).join(", ")
Please, note that it is necessary to replace nnnnn with the ID of the custom field.
