just in passing:
a family friend who was Jesuit Priest (also a practicing psychiatrist), told me a long time back that -- his local Jesuit chapter had adopted Buddhist "Walking (Mindfulness) Meditation", as part of their spiritual exercises. The Jesuits, of course, have practiced their own forms of meditation since the inception of the order.
my own friend who's an Episcopalian Christian, tells me that his own church, here on Long Island, NY -- served by the Episcopalian Franciscan order -- practices the Buddhist "Metta (Compassion) Meditation" regularly, every weekend. Of course, IMO -- aside from his Christian faith -- Francis of Assisi was a Buddhist in all but name.
there was Thomas Merton, the Trappist Monk & author of the "Seven Story Mountain", was a student & practitioner of Zen meditation.
in India, around the time of the later & more enlightened Mogul Emperors & possibly during the British colonial regime, it was customary for Buddhist Monks, Hindu Yogis & Muslim Sufis, to have regular gatherings & practice their different forms of meditation, in a group.