Apply the transformation to the object’s parent.
Grandparent
Apply the transformation to the object two levels
up in the scene hierarchy.
Snap Type
Only appears in Snap 2 points to 2 points. You click
two pairs of points on the two objects to align them. This option
controls what Maya does when the pairs of points are different distances.
Left
Snaps the first and third points you click,
and aligns the second and fourth points in the same direction as
the first and third.
Middle
Snaps the second and fourth points, aligns the first
and third in the same direction.
Right
Snaps the midpoint of the first and third points to
the midpoint of the second and fourth, and aligns the other matching
points in the same direction.