Drag it to the top of the scene tree
Add a Sprite2D as a child of Background
Set back.png as the Sprite's Texture
Select the Background node
Set Scroll Scale to 0.2, 1.0
Set Repeat Size to 576, 0
You can position the Background node
I placed mine at -247, 296
Add another Parallax2D node
Rename it to Middelground
Place it below Background
Set middle.png as the texture
Expand Texture properties
Enable the Region settings
Set width and height to 880 x 368
880 is the image width (176) multiplied by 5.
Now we have 5 mirror images!
To overlap the bottom half
Of the ocean and sky image
Select the Middleground node
Set the Scroll Scale to 0.6, 1.0
You may have to adjust the position of Middleground
In your Level01 scene too.