TopLevel Window switch with next button


Hello forum,
I want to learn Ruby and GTK. Have worked through some tutorials and get smaller programs to work.

I am particularly excited about this tutorial

But what I unfortunately have not found an answer and I hope someone can explain this to me.

Is it possible to draw several windows with GTK and to display this page via a next button without opening a new TopLevel window?

I do not want to close the window.
there should also be a back button. So the first window has to be brought back. The way Gtk :: Assistant does it.

However, I have read that Gtk :: Assistant is outdated, so I wanted to write everything myself.

Thank you