Understanding BIAB Styles

I grew up with the Yamaha Arranger Style system. I am finding it hard to understand the Biab Style system and how to adjust the style.

How do I create changes in the style like Variations 1,2,3,4 in Yamaha and insert them in the desired location on the chord sheet. I have been able to do few basic things but I am not getting the overall concept.

Is there any video on this or specific things written this subject ?


Thanks