Select a shape inside a boolean

Reach the parts a Union or Subtract is built from, including the cutters.

A boolean shows one combined solid in the viewport, so the shapes it is built from have nowhere of their own to appear - and a cutter has no visible geometry at all, being defined entirely by the hole it leaves. Selecting one in the scene tree draws it as a translucent amber body, through the solid it sits inside, so you can see exactly which shape you have hold of.

From there it edits like any other shape: change its size or position in the Properties panel, or drag the gizmo. A very dense imported mesh is outlined as a box rather than drawn in full, so selecting it stays instant.

This is what makes a wrong-looking Subtract diagnosable: if the hole is in the wrong place, select the cutter and move it, instead of undoing the boolean and starting again.

To reach every part at once — to hide them, recolour them, or delete one — right-click the boolean and choose Select children. It works on a rounded or hollowed shape too, where it selects the shape the modifier was applied to. Note that the parts it selects cannot themselves be fed to a new Subtract: a boolean’s children belong to that boolean, and Combine only ever works on whole top-level objects, so ungroup it first if that is what you want.

1. Expand the boolean in the scene tree and click one of the shapes inside it.
2. Or right-click the boolean and choose Select children to take all of its parts at once.
3. It is drawn as a translucent amber body so you can see where it sits.
4. Edit it in the Properties panel, or drag the gizmo to move it.