The picture in picture feature is not available on tvOS the same way it's available for iPad. Please file an enhancement request through our <Bug Reporting Tool> to let our tvOS engineers know that this is a requested feature. Here is the link: https://developer.apple.com/bug-reporting/
This is still possible to accomplish by manipulating the AVLayerPlayer. However, the video view will only be available within your application. Here's a link to the reference here:
Also, check out this Github for a "floating" action button. Much of the custom auto layout needed for a "picture in picture" view will be very similar, if not, the same.
Hope that helps!