I have a library module with a huge manifest. Also i have a application module with a huge manifest very similar to my library manifest but with package name changes. Now i
In Android Studio 3.3 you can also see Merged Manifest by clicking on Merged Manifest tab. It's showed at the bottom of the editor pane when you open your standard project manifest.
see documentation: Merge multiple manifest files
You find the manifest in your build folder, e.g.
/project/module/build/intermediates/manifests/full/debug/AndroidManifest.xml