Not sure what version you have of BIAB.

In 2013 under help click Index,click index tab if needed.
Enter Chord List, then click result answer.

This will give you all of the chords you can use within BIAB.
This may clear up your question a bit.
Make sure you review this list.

I just received a recommended book on chord progressions.
I did see something about a trio. But could not find it.
If you examine the help file chords, you should get your answer.

FrankB

Down The Street vs2015 12-03-2014
Win7, AMD QuadA8-5500,16GB,2TeraHD, Komplete 10
PG Ultra Plus 2016,Alesis 12USB, Sonar Platinum