Can anyone help me with background loading screen in godot

I want to make a simple and easy background loading screen in godot 3 but there are not much tutorials or demo available for godot 3

But I found this demo

But this is not an ideal loading screen because it just hide the existing buttons and make a progressbar in top of everything. I want that the progressbar with a custom background like a colorrect should be showing on top of everything that can hide all of the button and existing things but I can’t able to do that if I put a background after the loading finishe the progressbar hides but the background stays

make a new CanvasLayer node and put anything as child with its layer higher than the 0. this should make it looks like loading, on top of anything because the layer order is higher

It is above everything but it is not hiding after loading finished