Spanish Wikipedia says it has Agnew / Kelly / Nesbitt / Lambe:
https://es.wikipedia.org/wiki/Celtic_Woman:_BelieveBootleg, in this context, is an unauthorized recording, release, reproduction, etc. Basically it means it's not official (and not legal to sell it), though it's apparently been distributed enough to earn a place on Wikipedia.
I haven't heard this particular recording before (or maybe I have and just don't know it).
My best guess is it's a recording from a tour show or possibly the version that was released on "An Irish Journey" (a hard copy of which I don't have in my collection yet
). The version on that album I believe is either similar or the same as the version recorded by Celtic Woman and released on
Degemer mat, Bienvenue (an album by Bagad Lann Bihoue), which I did buy as a single.
