We have an issue hierarchy that uses 5 tiers (3 are in Jira Plans), in order as follows: Initiative, Feature Set, Feature, Epic, base-issues (and sub-tasks, but that is not needed for this query). We have Feature Sets that live in one Software Project, but are parented to an Initiative in another Software Project.
I need a query that will pull all of the child issues of an Initiative, and then the child issues of the returned Feature Sets, and then their child issues, and so on. I have used "Parent in ()" function for most queries so far.
In essence, I need to pull a list of Feature Sets used a Parent Initiative, and then reference the output of that query (the live list of Issue Keys) in another query to pull all the child Features of those Feature Sets.