Layer > Reset Position undoes any adjustment that's been done to a layer's position, whether through the Move Layer tool or other layer commands.

It returns drawing layers to their full resolution (1:1 scale), undoes any rotation, and moves them to the upper-left corner of the frame.

If a layer is nested under another layer, its scale, position, and rotation will be reset to the same as its parent layer's, which may not be aligned with the frame.