Achive Hierachi Scene Foldout Style in Custom Editor Window

Hey there!
I'm trying to achieve the MultiScene Hierarchy Foldout style. I thought it would be included in EditorStyles or something, but after lots of searching, I can't find the way to replicate it anywhere.

This is what I'm trying to achieve:


(Notice the gray divider at the bottom)

Does anyone know how to achieve this?
Thank you!!

 

I took a quick look with this tool: https://wiki.unity3d.com/index.php?title=Show_Built_In_Resources
but sadly could find the exact match in the list. Maybe I was not searching thoroughly enough or maybe you will find another style that satisfies your needs. If you don't find it in that list, I fear you won't find it at all.

 

The scene hierarchy background style is:

Code (CSharp):

1. GUIStyle sceneHeaderBg = (GUIStyle)"ProjectBrowserTopBarBg";

And the style of the option icon on the right is:

Code (CSharp):

1. GUIStyle optionsButtonStyle = (GUIStyle) "PaneOptions";