Arrange Widgets in QSplitter

[stampede]

If you use designer, open the right click menu while selecting both layout and third widget, there will be an option to arrange in a splitter.
If you want to do that from the code, create a fourth widget and add the layout to it. Then arrange fourth and third widgets in a splitter. Code generated from designer form looks like that, try to create a test form and generate the code (using 'uic') for reference.