let's take for example I got this According to FFmpeg usage to take Bluray as input we can use

ffmpeg -i bluray:"path/to/bluray/" -map 0 -c copy -c:a flac remuxed-bluray.mkv

and for this file, it will be something like

ffmpeg -i bluray:"[BDMV] Oshi ga Budoukan Itte Kuretara Shinu - Vol.01" -map 0 -c copy -c:a flac remuxed-bluray.mkv

The above gives only one output but as you can see from the file structure its not only one episode but consists of 6 episode and rest BD menus.

So what should I use to get all the 6 episodes and bd menus separately?

Please Don' t give me that just do the following

ffmpeg -i "[BDMV] Oshi ga Budoukan Itte Kuretara Shinu - Vol.01/BDMV/stream/00000.m2ts" -map 0 -c copy -c:a flac remuxed-bluray.mkv

as input and encode it. Since I know this, but due to poor documentation very less is provided about Blurays encode