Hi,
After lots of researching and trying out things, I was able to pair a bluetooth controller over a bluetooth dongle with rasbian over the terminal.
My primary purpose with this post is to reach out to the retropie developers to share my solution in order to integrate it cleanly into retropie.
For all the users who struggled, and failed, and who are still struggling of finding a way to pair their bluetooth based gamepad over their bluetooth dongle. Can simply leave for me a message in this thread, I’ll try to post my solution as soon as I can.
Looking forward for the feedback.