I want the ability to create a report the that show how long an issue is in a a specific state but only in the Active Sprint. I found the following Filter
you are almost there, you can add in the calculation formula a condition of Start date existence to avoid including future sprints. Also, I would add ordering by sprint start dates as there could be several ongoing sprints:
Aggregate(
Order(
Filter(
[Sprint].[Sprint].Members,
NOT [Sprint].CurrentMember.getBoolean('Closed')
AND
NOT isEmpty([Sprint].CurrentMember.get('Start date'))
),
-- ordering by start date across all boards
[Sprint].CurrentMember.get('Start date'), BASC
))