Determine which app is drawing on top of other apps?

Is there a way to determine which application is drawing on top of other applications?

For example, Facebook Messenger app can draw the chat bubbles on top of everything, but how do I know which app is doing this?

My problem:

I have an app which is drawing ads on top of everything and I wanna know which app is doing this. Not just to uninstall it, but to warn everyone that uses this app. (I didn't install any application recently and I already verified the recent updates.)

I tried to use the Dump View Hierarchy for UI Automator from the Android Studio, but it seems that the applications that draw on top can't be selected this way.

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