I propose that we add a "goals" or "sub-milestones" feature. This feature will allow managers to set a goal to close a certain number of issues before a specific due date.
"We need to close 50 frontend bugs this month" - An enterprise team somewhere in the universe
Like a milestone, a goal should have a start date, an end date, some boards and a burndown chart.
Unlike a milestone, individual issues would not be assigned to individual goals. Instead, any goal has a list of labels that it will use to query all issues with that label. It will also have a "completion threshold" number, which would be the number of issues that need to be closed before the goal can be closed and also the number of issues that need to be closed before the due date.
Note: Filtering by label is used as the most important example, but, we should also offer to filter by milestone.