Are you wanting the book or the video? I own a copy of the book by that name, but I've not heard of a video by that name.
I do have a video about caves in general that included a section about Lechuguilla; Perhaps that is what you are thinking of?
This same video also had a rather lengthy segment about Mammoth Cave, in particular about the connection that made it the world's longest.
It is available on Amazon:
https://www.amazon.com/Mysteries-Underground-Richard-Kiley/dp/B004FN25O2Or you can watch it for free on YouTube:
https://www.youtube.com/watch?v=bq7-bl2wRsgIf you are looking for the book called Lechuguilla: Jewel of the Undergound, it is also available on Amazon:
https://www.amazon.com/Lechuguilla-Jewel-Underground-Urs-Widmer/dp/3908495016Also you can find it on Ebay.
Trogman