Using the left mouse button, drag the tab of one of the displays in the direction where you want it to appear. In the illustrations below, the Geometry Scene 1 display tab is being dragged to the right so that the display will occupy the right half of the Graphics window.
A red outline will appear around the scene display as you begin to move it.
As you continue to move the mouse in that direction, the outline changes to show how the Graphics window will be split between the scenes.
Let go of the mouse button. The scenes will share space in the Graphics window.
You can use the same technique to divide the Graphics window further among more scenes.