Is there anyway that we can have Custom Layouts e.g. as defined at https://doc.qt.io/archives/qt-4.7/examples-layouts.html
inside the Qt Designer ?
What would be the process to add such custom layouts in the Qt Designer? Can anyone guide about the steps involved for such custom enhancement in Qt Designer.
You can't create custom layout right inside QtDesigner. Instead you can write your layout as a plugin for QtDesigner. After this you can open QtDesigner and just drop your own layout to the form as any other widget in the Qt collection.
See this quide to find out how to write your own plugin for Qt. It's not so difficult.