Current State:

The internal comment visibility functionality have been announced for JSM cloud but currently, there's no option to make these changes through automation rules or any endpoints.

• https://community.atlassian.com/forums/Jira-Service-Management-articles/New-Restrict-your-internal-notes-to-project-roles-or-groups/ba-p/2704909 

Proposed Future State:

It would be better to have the ability to update the internal comments in an automated way to restrict internal notes based on user's group.

Workaround:

Currently there's no known workaround for this work item.