From build mode, you can open your build menu by pressing the recessed menu button on your left controller. If you point your laser pointer at the header of this or any menu. You can then hold down the trigger to move the menu around. While the trigger is held down, you can push your thumbstick left or right to enlarge or shrink the menu. And forward or back to reel it in or out. When you are done, you can position the build menu relative to your view, and it will stay there even as you move around.
Important
If your build panel is ever out of reach you can return it to your pointer by pressing and holding the recessed menu button on your left controller. With the recessed button pressed, the build menu will also follow your hand, allowing for easier positioning.