Draw overlay quad/shapes when background quad is zoomed in

Hi,

I'm trying to draw an overlay quad/shape on top of another quad.

Now i could have my background quad zoomed in (using ortho camera) while i'm trying to draw my overlay object. 

Thus, what i really want is to draw the overlay shape which takes into consideration how much i'v already zoomed in.

As currently it doesn't expand/enlarge when i zoom in and thus keeps the overlay shape of the same size.

Do i need to manually enlarge the shape and then draw or could it be all done in shader ?

Any suggestion how i could approach this.

Note: Using SharpDx & C# & Directx11