Agile: Sort by priority, maintaining sub-task grouping with parent

[Paul Da Silva]

My team vastly prefers having the agile board sorted by priority, instead of rank. This has not been a concern to date; until we started to venture further into using sub-tasks.

It appears that the only way to ensure sub-tasks will be listed directly under their respective parent items is to use sorting by rank.

Is it possible to keep sorting by rank; but also have sub-tasks grouped with their parents? This is a huge deal breaker for sub-task use; so any workaround would be appreciated.

Note: I'm using the cloud version

[Nic Brough [Adaptavist]]

That makes sense, because sub-tasks can have different priorities and you're choosing to order by them.

In the past, I've created a custom field called something like "parent" which is derived from the actual parent, so I could do "order by parent", but that still wouldn't really help you because you need to decide where the priority actually matters.  I suspect you want to sort the list by parent priority, then the subtasks within it.

I think you could create such a field on Cloud using the Script Runner or other scripting add-ons to populate a text field.  The logic to populate it would need to generate a composite sortable string of <parent priority><parent issue key><subtask priority> for the subtasks and <parent priority><parent issue key><dummy that lands before any subtask priority> on the parent issues.

[Karl Renner]

I am working on a similar problem trying to use swimlanes grouped by story (to keep subtasks with the parent), and having the swimlanes in priority order.  If you're willing to always have at least 1 sub-task for each parent, my progress may be of use:

1. A filter query that returns only the sub-tasks, will sort the story swimlanes so that the highest priority sub-tasks define the order of the board.
2. A filter query that also includes the parents, does factor in the priority of the parents, but a high priority sub-task will move a low priority swimlane up the page - no good. 
3. A filter query that sorts by "issue type" then by priority, works fine provided we only use two issue types - stories and sub-tasks.  Because we have many types of sub-tasks and parents this doesn't work for us.
4. The solution I am using for now, is to define a separate set of priorities for sub-tasks and parents such that all sub-task priorities are below the parent priorities. This is more confusing for users but should meet our needs until we've seen a payoff from the board.

The payoff is that it will allow us to create a board with only sub-tasks where the swimlane sequence is "expedited tasks/stories/bugs" followed by "stories furthest along the workflow". 

Nic's solution above would also work for our needs (I'd label all stories, tasks and bugs with "1" and all sub-tasks with "2").  But my approach used a different "JIRA Server only" plugin.