You enter a slash root note exactly as you showed, with the chord, a slash, and the note you want the bass to play.

You're going to have a challenge doing the Am/G on the And of 2 immediately followed by the F on beat 3. BIAB handles the And of a beat as a push earlier from the next beat. You can't have both in the same measure, even if you stay within the limit of four chords per measure.

There are ways to do it, though. One method is to double the number of measures each chord occupies, and adjust the tempo. Another is to check out the Expanded styles on NortonMusic.com that were written by a third party to solve precisely this problem.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.