I don't know when these were posted, but I noticed them in the AVFoundation documentation last night. There have been a lot of questions about working with this format, and these are useful. They also include code samples.
Reading multiview 3D video files: https://developer.apple.com/documentation/avfoundation/media_reading_and_writing/reading_multiview_3d_video_files
Converting side-by-side 3D video to multiview HEVC: https://developer.apple.com/documentation/avfoundation/media_reading_and_writing/converting_side-by-side_3d_video_to_multiview_hevc