Comment Fields provides various feature sets that you can use for your comment operations. Once you install ACF, Comment custom fields are automatically generated in your Jira's custom fields list.
First Comment
Last Comment
First Commenter
Last Commenter
Last Commenter is Reporter
First Commenter is Creator
First Commenter is Assignee
Last Commenter is Creator
Last Commenter is Assignee
First Comment Date
Last. Comment Date
Public Comment Count(for JSM)
Internal Comment Count(for JSM)