At the time of publication, there's no way to play 3D Blu-rays or 360 degree videos on PSVR2. We purchased a 3D Blu-ray to test this, but were greeted with an error message explaining that the PS5 isn't compatible with 3D Blu-rays, and were instructed to use a player that is. This error appears even when you attempt to play films while wearing the headset.
Similarly, we were unable to get any 360 degree videos running from a USB stick, as the format is not currently supported by the PS5's built-in Media Player. In both instances, it's possible Sony could patch in support at a later date, and we'll update if anything changes.
It's worth mentioning that all this means there's no way to play VR porn on PSVR2 right now, which was a popular feature on the original PSVR headset.