I want to bring the point of the crown in front of the heart while leaving the rest behind.
If you have the crown and the heart as separate layers, duplicate the crown, but the copy on top, and erase most of it except where you want it to be above the heart.
If it's a single image, no way without redrawing things on a layer above. This said, these are straight lines, so it's not difficult:
- Create a path (red line)
- Sample the color of the crown
- Add a new layer
Select>From pathand bucket-fill the selection
- Set the FG color back to black, remove the selection, and
Edit>Stroke path, in
Linemode, with a width of 1 px
- With the eraser tool erase the two black segments at the bottom