Bug watcher supports special watcher types additionally to users: external email addresses, project roles and groups.
Manage non-Jira users as project or filter watchers. Notification of external users is a long-awaited feature request by the Jira community. Bug Watcher allows users with Manage Watchers permission to add external email addresses to project watchers.
These external users will receive notifications for events where watchers are set in the Notification Scheme of the project.
Additionally to projects, Bug Watcher allows you to add external watchers to your filters.
Project roles and groups can also be set as watchers in the projects or issues.
Go to your Project. Choose Bug Watcher icon in the left sidebar and click on Watches.
Add users, email addresses, Project Roles and Groups to project watchers in the Manage Project Watchers section
Add the Issue Watchers custom field and add it to an Issue screen in your Project. You can add special watchers to the issue via the Issue Watchers custom field: users, email addresses, roles and groups.