Trying to zoom out the god view in overview diagram

I am trying to zoom out the overview diagram but its not working. I would like to zoom out, so that I can see more contents from the observed diagram.

I read that, a change of scale or zoomFactor might not work on Overviews, since the scale is probably reset when setting the observed diagram.

Please suggest if there are any alternatives that I can try.

The implementation of Overview sets:

    this.autoScale = go.Diagram.Uniform;

You need to set it back to go.Diagram.None.

However, doing so will mean that the Overview Diagram will not automatically zoom the Diagram.scale to show the whole Diagram.documentBounds of the observed diagram.

I haven’t tried this, but you could implement a “DocumentBoundsChanged” DiagramEvent listener on the observed diagram to call Diagram.zoomToFit on the overview. That way as the document changes size the overview will be zoomed normally, but you will be able to zoom in and out in the overview.