So the black oval is like a scaled version of the screen rotated 90 degrees, and you want the mouse over that to translate to a position over the view?
Let’s try and simplify it a bit first. If you make the oval not rotated and move the origin to the center then the calculated xy position on the view would be:
(Mouse.x(1)-oval.x)/oval.width*viewportWidth(0)+scrollx
(Mouse.y(1)-oval.y)/oval.height*viewportHeight(0)+scrolly
Note: mouse.x(1) is the mouse position on the hud layer.
Now let’s make it work if the oval is rotated 270 degrees like you have. Basically (x,y) rotated -90 will become (y,-x), but you have it vertically flipped (y,x). So swapping things around a bit the xy formulas will be:
(Mouse.y(1)-oval.y)/oval.width *viewportWidth(0)+scrollx
(Mouse.x(1)-oval.x)/oval.height *viewportHeight(0)+scrolly