While BIAB can convert a mono audio file to MIDI, as far as I know it can't separate the various drum parts from the drum stem into separate MIDI files.

I used a site called fadr. I uploaded my BIAB drum audio and it gave me a GM drum file. I dragged that file into Addictive Drums 2, set up AD2 to receive General MIDI, and it worked perfectly. Everything was in the right place, it sounded like the BIAB file, but now I could change the drum sets and edit the patterns. I made hundreds of changes to tailor the drums to the specific needs of my song. It was so much easier to start with the BIAB drum patterns--which I liked--rather than try to make the whole thing up from scratch on Addictive Drums.

There are other companies that do this conversion, but I was happy with my experience on Fadr. They also separate audio stems, but for drums it's not as good on audio--just Kick, Snare, and Other Drums.

They have some free features, but I paid $10 for a month, as I wanted wav files and not mp3s for the audio stems.

Check out my YouTube video on BIAB at https://youtu.be/_vel48tBLKY
and please subscribe to my channel.