Default value for "Comment Viewable By"

[Synaptics Tony Chang]

If you want to set default value for "Comment Viewable By" globally, here is steps : 

[ Default Group ]

1. Decide the group, e.g. jira-developers

2. Replace following code in the file atlassian-jira/WEB-INF/classes/templates/plugin/comment/system-comment-field-edit.vm

#if (!$comment && $defaultLevelEnabled)
    #set ($selectedCommentLevel = "default")
    #foreach ($level in $groupLevels)
        #if ($level == 'jira-developers')
            #set ($selectedCommentLevel = "group:jira-developers")
        #end
    #end
#else
    #set ($selectedCommentLevel = "")
#end

instead of 

#if (!$comment && $defaultLevelEnabled)
    #set ($selectedCommentLevel = "default")
#else
    #set ($selectedCommentLevel = "")
#end

3. Replace following code in the file atlassian-jira/WEB-INF/classes/templates/jira/global.vm

#if ($isRolePresent)
    #foreach ($level in $roleLevels)
        #if($level.id && $selected == "role:${level.id.toString()}")
            #set($currentSelection = "$i18n.getText('viewissue.comment.visibleby') <span class=redText>$level.name</span>")
            #set($locked = true)
        #end
    #end
#end
#if ($isGroupPresent)
    #foreach ($level in $groupLevels)
        #if($level && $selected == "group:${level}")
            #set($currentSelection = "$i18n.getText('viewissue.comment.visibleby') <span class=redText>$level</span>")
            #set($locked = true)
        #end
    #end
#end

instead of

#if ($isRolePresent)
    #foreach ($level in $roleLevels)
        #if($level.id && $selected == "role:${level.id.toString()}")
            #set($currentSelection = "$i18n.getText('security.level.restricted.to', ${textutils.htmlEncode($level.name)})")
            #set($locked = true)
        #end
    #end
#end
#if ($isGroupPresent)
    #foreach ($level in $groupLevels)
        #if($level && $selected == "group:${level}")
            #set($currentSelection = "$i18n.getText('security.level.restricted.to', ${textutils.htmlEncode($level)})")
            #set($locked = true)
        #end
    #end
#end

4. Restart your JIRA application

[ Default Role ]

1. find project role id in [JIRA Administration] -> [System] -> [Project roles], e.g. Developers is 10001

2. Replace following code in the file atlassian-jira/WEB-INF/classes/templates/plugin/comment/system-comment-field-edit.vm

#if (!$comment && $defaultLevelEnabled)
    #set ($selectedCommentLevel = "default")
    #foreach ($level in $roleLevels)
        #if ($level.id == 10001)
            #set ($selectedCommentLevel = "role:10001")
        #end
    #end
#else
    #set ($selectedCommentLevel = "")
#end

instead of 

#if (!$comment && $defaultLevelEnabled)
    #set ($selectedCommentLevel = "default")
#else
    #set ($selectedCommentLevel = "")
#end

3. Replace following code in the file atlassian-jira/WEB-INF/classes/templates/jira/global.vm

#if ($isRolePresent)
    #foreach ($level in $roleLevels)
        #if($level.id && $selected == "role:${level.id.toString()}")
            #set($currentSelection = "$i18n.getText('viewissue.comment.visibleby') <span class=redText>$level.name</span>")
            #set($locked = true)
        #end
    #end
#end
#if ($isGroupPresent)
    #foreach ($level in $groupLevels)
        #if($level && $selected == "group:${level}")
            #set($currentSelection = "$i18n.getText('viewissue.comment.visibleby') <span class=redText>$level</span>")
            #set($locked = true)
        #end
    #end
#end

instead of

#if ($isRolePresent)
    #foreach ($level in $roleLevels)
        #if($level.id && $selected == "role:${level.id.toString()}")
            #set($currentSelection = "$i18n.getText('security.level.restricted.to', ${textutils.htmlEncode($level.name)})")
            #set($locked = true)
        #end
    #end
#end
#if ($isGroupPresent)
    #foreach ($level in $groupLevels)
        #if($level && $selected == "group:${level}")
            #set($currentSelection = "$i18n.getText('security.level.restricted.to', ${textutils.htmlEncode($level)})")
            #set($locked = true)
        #end
    #end
#end

4. Restart your JIRA application

Reference Robert Wolf's comment in https://jira.atlassian.com/browse/JRASERVER-9091