In 2D, sprites are drawn in the same order in which they appear in the scene tree. So if you have this:
Root
- Sprite1
- Sprite2
Then Sprite2 will be on top of Sprite1.
If Sprite1 is a child of Sprite2, you can check the Behind Parent
option in the inspector for Sprite1.
Finally, if no other solution work, you can adjust the Z
property.