Its been several times, I tried this solution mentioned in the following link
https://confluence.atlassian.com/display/JIRA/How+do+I+assign+issues+to+multiple+users
I created a custom field - Group Picker. A group of 2 users has been created. I also did the Notification thing which has been mentioned. But, I still could not find a "group option" in assignee tab of the issue to be be assigned.
Is there any other way to do this? Labels and Notes - can they be useful. Although, currently there are not many users I would still need to know the same for near future. I am a Project Manager & Scrum Master, I have all the rights as JIRA System Administrators. However, I am not the owner.
Thanks
Suyog