A Pen by Nithin K.

index.html

<script src="//tinymce.cachefly.net/4.0/tinymce.min.js"></script>

<form method="post" action="something">
    <textarea name="content" cols="100" rows="15">content</textarea>
    <input type="submit" value="Save" />
</form>

script.js

tinymce.init({
    selector: "textarea",
  setup: function(editor) {
      editor.addButton('report_design', {
        type: 'menubutton',
        text: 'IMAGE',
        icon: false,
        menu: [
          {text:'Data', menu:[{text:'sub1'},{text:'sub2'}], onclick: function() {editor.insertContent('$%<i><%= "menu2" %></i>%');}}
            ]
      });
    },
  
    toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image | emoticons | forecolor backcolor | print | report_design "
 
});

TinyMce-sub-menu.markdown

TinyMce sub menu

Customizing Tinymce editor. Trying for an image to be displayed on a menu button named IMAGE.

A Pen by Nithin K on CodePen.

License.