virtualbox – two windows appear at the center but one would be activate

I have a VirtualBox guest window and an editor window placed at the center of the screen. I want to see the editor while working with the VirtualBox window. To do this, I decreased the editor window’s transparency, but my problem is that the editor window is active. How can I disable the editor window and just see it? In other words, I can’t work with the VirtualBox window when I click the center of the screen because the editor window would be selected.