Trouble with unity calls Android native view

Hi，everyone. I have a demand like this： In my Unity project, I need something special view（In fact it is a function developed in Eclipes IDE with android sdk & adt）. After finished these functions, I exported Android project to *.jar file and integrated to my unity project. This process references unity doc：

https://docs.unity3d.com/Manual/android-GettingStarted.html

https://docs.unity3d.com/Manual/PluginsForAndroid.html

It runs good.

I want the android view behind the unity player view, but question is the android view alwalys display above unity player view.

Sometimes I need like this:

But I only get this：

（Pictures only explain my question）

Android view from *.jar file that developed in Eclipes IDE always obscured my Unity views. Did anyone meet this problem？Can anyone give me some help？

Thanks in advance. @tnetennba @mikolo