Bar Settings mutes also are working on my version of BIAB.

Audiotrack's answer is easy and Simon's solution provides more control on track volume. There's a third option that allows BIAB to provide the best quality and smoothest transition between the track audio and the muted silence. It's as easy as Audiotrack's method; It's activated from Bar Settings Window the same as his answer. The Bar Settings Dialog window can be opened and accessed in the Chord View, Tracks View, Notation, Piano Roll and the Audio Edit/ACW view.

BIAB has a special RealTrack designed especially for arrangement situations described in the initial post. Inserting RT-1152 Silence onto a specified region on a Mixer Track with a RealTrack assigned, tells BIAB that you, the user, wants silence for that specific selected track region. It can be a Bar, several bars or like in this case, an entire chorus.

Telling BIAB where you want silence works the same as telling BIAB what chord you want to sound in a bar or series of bars. Knowing where you want silence, BIAB generates endings and intros encompassing material just before the silence and the material just after the muted region creating a 'Smooth Transition'. This creates an arrangement performance that's plays like a real session player would approach playing the song and knowing where to stop and start.

The difference in quality is displayed in the two attached screenshots of a post-generation edit using Bar Settings or Volume Automation compared to BIAB generating the same region of silence as it generates the track.

I used Audiotrack's image of the Bar Settings Dialog to show the RealTrack Button in Bar Settings. In my demonstration screenshots, I selected Guitar 3 to mute bars 3,4,5 using the track's post-generation mute/ Return to Normal selection and having BIAB generate the silenced bars 3,4,5 region on the track in the second screenshot.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
F5 set to mute bars 3-5.jpg (311.6 KB, 71 downloads)
1152 set 3-5.jpg (279.08 KB, 71 downloads)
2025-02-18_3-24-08.jpg (45.67 KB, 69 downloads)
RT-1152.jpg (133.72 KB, 70 downloads)
BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.