Field Mirror Documentation explains both product and technical documents!
2
Tip
All you need to do is config Mirror rule and add Mirror custom field to Jira project and reflect any Issue data on create/edit screen!
3 basic steps to get started with FMJ
Field Mirror for Jira Software is a plugin for software teams that need to organize and track their work. FMJ is incredibly flexible and can be customized to work, meaning teams of all kinds can enjoy increased productivity and visibility as they march toward releasing amazing software.