Hi,
I have a project for which I need to create a long term plan and link some externaly defined milestones by managment to my setup
Preconditions:
1. We have cloud instance
2. I use paraller sprints functionality (2 weeks sprints)
3. There are about 12 scrum teams for which I can have multiple future sprints created so that Story can be dragged to any future sprints for long term planning
4. Epic = Scrum Team name so that it is easy to filter backlog (User Story have mandatory Epic Link field)
5. Groups = Scrum Team
6. I use Issue Security field to manage who can see what and who can drag items to sprints. Multiple groups can be assigned to each issue security (for managing cross domain work and for somebody who works in two or more sprints)
What I need
**I Received a list of milestones (+6 months plan) from management that are divided by dates. For each week for a particular Scrum Team I have about 2-3 Milestones (Total about 7 milestones per sprint for each Team)
**Management wants to track milestones by knowing how many user stories have been completed during each sprint for those milestones for each and every team
**I need to see User Story related to particular milestones + I want to have a good visibility of this setup (possible gantt)
I wanted to use Issue Picker Custome Field but this only work on server app. There is Big Picture or Portfolio for Jira but not sure this will help
ANY IDEAS ? 
Thanks