@JohnH Via script, for example. You need to be more specific about the task.
Idea is next. Input files has fixed (constant, not dynamic) names and recorded on same hotkey press from replay buffers of two instances of portable OBS (for portable see:
https://obsproject.com/forum/thread...»-when-opening-app-settings.82157/post-346499) or from "Source Record" plugin filters (if you are lucky - its replay buffers will work same way,
https://obsproject.com/forum/resources/source-record.1285/). On same hotkey press the script renames mentioned files for you (file names are predefined, so no problem to to make few attempts while some files may remain in use by buffers), after renaming complete - you can write at this place new files, same names! And recently renamed files goes to playlist. Thus, as soon as you has few files in the same folder you can rename them, then add renamed to VLC source for playback, and then can write new files instead of recently renamed.
"multi-files-replay.7z" 7zip archive, ~4KiB to download, CRC of the archive MD5: DF5CE4229B3DE5B6E411F329C5FC92B5
inside: "multi-files-replay.lua" file.
The script only doing renaming of the files and adding files to the playlist of VLC source. It doesn't saves replays or starts replay buffers (but can be triggered by same hotkey as "save replay" if needed).