How to hide/disable "Add Comment" section in Asset Timeline

One of the ways to customise this would be to :

1. Get the current userGroups and check if they fall in the group for which commenting should not be allowed. Lets, assume the variable as isUnallowedUg.

function getLoggedInUserID() {
    var currentUserId = "";
    var currentUserInfo;
    var CURRENT_USER_JSON_PATH = Granite.HTTP.externalize('/libs/granite/security/currentuser.json');
    var result = Granite.$.ajax({
        type: "GET",
        async: false,
        url: CURRENT_USER_JSON_PATH
    });

    if (result.status === 200) {
        currentUserInfo = JSON.parse(result.responseText);
        currentUserId = currentUserInfo.authorizableId;
    }
    return currentUserId;
}





function getUserGroups(userID)
    var isMemberOfGroupEveryOne=false;

    $.ajax({
        url: "/bin/security/authorizables.json?filter=" + userID +'&_charset_=utf-8',
        async: false,
        success: function(result) {
            if (result) {
                $.each(result.authorizables,function(index,authObj){
                    if( (authObj.id !== userID)){
                        return;
                    }else {

                        $.each(authObj.memberOf,function(index,memberOf){
                            if(memberOf.id === 'everyone'){
                                isMemberOfGroupEveryOne=true;
                            }
                        });
                    }
                });
            }
        }
    });
    return isMemberOfGroupEveryOne;
}

I have used everyone for demo, you could use your custom group.

2. if isUnallowedUg is true, you would be hiding the class cq-common-admin-timeline-toolbar using display: none in CSS.

Hope this helps, thanks!