In Agile development an Epic is just a large story that cannot be completed in an iteration.
Where I work an Epic is also a bucket of work that 2 or more teams will work on to complete it. Team team will have stories that roll up to the Epic. The same for an initiative.
Currently we use a multi-select custom field to chose more than one team, but oftentimes people do not set both Team and the custom field.
It would be very helpful is we could allow Epics and above to allow multi teams selections, but story and below only allows single team selection.
I'll attach a picture that illustrates my thinking.
On Epics and above we need to assign more than 1 team to those tickets, so we created a custom field in Jira, called "Teams". We needed to do this because the built in Jira field of "Team" will only allow one team to be set.
So for stories that are worked by only 1 team it would we would set the Team.
For for larger Initiatives or Epics many teams will have be assigned to work on them.