If you are referring to the BD chapter menu on the BD disc, JRiver is unable to display that or let you select a specific chapter by name from it for BD-A or BD-V. That is unfortunately the way it is, though many would love to have that chapter menu capability in JRiver. BD-A is just a limited variant of BD-V that has a fixed video content.
BD-As are ripable to a number of different formats - ISO, MKV, etc. which are video-capable formats. There are a variety of tools that can extract audio from that resulting decrypted folder on a chapter by chapter basis - into individual Flac files, for example. DVDAE is one such tool. Those can then be tagged and included in your library just like other Flacs, etc.
JRiver has a Particles feature mentioned in this forum for prior JR versions. That can be set up to allow access to individual "tracks" or chapters inside the BD file based on chapter timing data you supply or which is occasionally provided by external websites, but mainly for BD-V movies.
All are not the greatest and a ton of agonizing work, I am afraid. So, I have avoided incorporating BD-As into my main music library, sadly.