Open a Toolbox and select the Free Select tool.
Click on the layer called top, and click on the eyes of the other layers until only the layers naked and top are visible.
Make sure the layer "top" is selected, and select around the top, leaving some space.
Then ctrl-i to invert the selection, and delete to remove it.
Do the same procedure on the bottom layer, selecting the bottom.
Example from Dakun Art
Finally, select the layers you need (naked and top or bottom) and click on File -> Export to save it.