How do I create a burn down report view.that shows all projects in a combined board

[Vlad Pierre]

I have created a board that has all the projects were working on ..about 6.  would like to have a view that shows all the sprints combined..as they are all the same duration..so instead of seeing just one project on burndown..I would like to see all of the ones included in board

[Deleted user]

The JIRA Burndown charts works against data on a given Sprint, not the board's filter.