It is not possible to assign one issue to more than one user at the same time. The most common suggestion is to create one sub-task for each person.
However, if you don't like to do this, you can also create a custom-field of the type multiple-user-picker and show it on the sub-task screen. All users can now search for issues where they are part of this field.
Please not that a custom-field will not work like the system-field "Assignee" for reports as e.g. User-Workload or filters e.g. "Assigned to me" and other such things.
JIRA doesn't allow this feature directly to avoid overloading. However, you can do this. Refer this doc.
I would prefer the second option to manage via a group (multi picker custom field). You can give permissions to that group as similar as Assignee
Badges are a great way to show off community activity, whether you’re a newbie or a Champion.Learn more
Hi Atlassian Community! My name is Shana, and I’m on the Jira Software team. One of the many reasons this Community exists is to connect you to others on similar product journeys or with comparabl...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs