In CM you can open 3 different windows. Click the icon of the page that you want to edit while pressing one of these 3 keys:

Shift key: opens the page in the main winndow

Ctrl key: opens the page in the bottom window

Alt key: opens the page in the right window

You can open or close the docking windows using the blue arrows

You can resize each window at the size you prefere selecting the border of the window.