Overlay in combination with HDR colors,

I am creating a 2D application that uses HDR colors on some components in order to use a bloom effect in post processing.

Using a canvas image, I am trying to create an overlay for a menu that is black and 80% opaque. The components using HDR shine right through the overlay, probably because the intensity of the colors is so high. This makes the menu unreadable. How can I create an overlay so that the intensity of all HDR colors of underlying components are displayed like regular colors?,

I found that the way to go is to use camera stacking using a base and overlay camera. The base camera renders the game world and applies the bloom effect. The overlay then camera renders the UI on top.