How can I restrict administrator access to a particular board?

[Heather Palazzo]

We have an increasing number of users with admin permissions. We would like to restrict admin rights to just 1 board. TO: Prevent changes to other team's boards, Prevent assigning stories across boards and across sprints, Prevent visibility to other team's sprints. 

[Nic Brough -Adaptavist-]

Administration rights really does mean administration, and you need to take a step back and think carefully about it.

This is not something software can help you with.  Why are you having "an increasing number of users with admin permissions"?  A Jira system with a hundred thousand users should never need more than 7 admins (and I've looked after much larger ones with only 3 admins), so I really do have to question why you have too many.