ExtJS Create new panel programatically

Good morning,

I am trying to create a widget in a TabPanel extending Multifield Widget, when a field in the multifield is created this one creates a new Tabpanel in the Dialog. But the Tabpanel created, its content is not looking like if the tabpanel is created in the dialog. Someone knows how create tabpanel programatically and dynamically?

    var myPanel = new CQ.MyPanel({ });

    dialog.insert(positionPreCalculated, myPanel);

    dialog.doLayout(true, true);

This code below is that I am trying to do.

Any idea would be most appreciate.

Miguel.