Xcode Interface Builder Tile Window

hide the Interface Builder overlapping Tile Window

If you want to hide the minimap, there is a menu: Editor > Minimap
This works both for canvas (shows / hides a storyboard overview) and code (shows / hides a reduced view of full code on the right).

If this not your problem, could you explain (if possible with a drawing sketch in the answer) what you get and what you expect ?

Note: At the top right of Xcode window pane, you have 2 buttons.
The leftmost (horizontal lines and a rectangle) let you select layout (Automatic, Canvas on right, canvas on left). Is it what you are looking for ?