Menu > Edit > Move Object
Select the body
Motion: CSYS to CSYS
Once aligned to Absolute your geometry still might not be parallel to the desired plane, so you can use Motion: Dynamic to rotate the geometry accordingly and, if necessary, move it along an axis to the desired position.
What did you have set for "Result" on the Move Object dialog. If it's set to Copy Original and there's a lot of distance between the original body and the copy then your display has fit the screen to show both objects. If you used Move Original, there could also have been other objects such as curves or points, in the original location that were not moved along with the body. Again, the Fit command fits the screen to show all objects, so it's likely you have some geometry still at the original location.