Importing Multiple Unity Project as a library inside Android Project

I have exported Unity Project as Android Project. later I have converted them into android libraries. for this conversion I am following below link:

now I want to load those different libraries on click of different buttons inside Android Project. when I run the project, the output of the project should be
while clicking on seprate buttons, it should load separate Unity Project (which I have imported as a library inside Android Project). instead of this output,
the project results specifically any single library.

for e.g. button_1 should load library_1 and button_2 should load library_2, but instead of this output, the output which I am getting is
either library_1 is loaded on clicking of any buttons or library_2 is loaded on clicking of any buttons.
Unity version that I am using is 2017.3 and Android Studio 2.3.3.

@MichalisGratsias
I too did the same, but i am getting manifest merger errors.
https://stackoverflow.com/questions/54418955/manifest-merger-failed-when-adding-multiple-unity-game-as-library
Can you post your Manifest which would help us solve the issues.

@unity_0c_XV8OvptKpNw Sorry, I don’t have that manifest anymore.