Being
I get the impression we are one being.
Differences between individuals are superficial, given all life on earth fits into a tree, we're all composed of the same elements and all elements are composed of the same particles.
The United States has a motto E pluribus unum, which is latin for "out of many, one."
In the 1972 movie Solaris (and presumably the book it's based on), the ocean and the humans floating on it interact deeply.
Acupuncture has a notion of chi, which is freely available.
"Yoga means union", a phrase I attribute to the community around Paramahansa Yogananda.
In Fourth Uncle in the Mountain by Marjorie Pivar and Quang Van Nguyen, the uncle says anything that comes to mind in meditation is a distraction, but doesn't say what it's a distraction from.
The On Being podcast seems appropriate to mention here, though I haven't yet come across an episode specifically mentioning the notion of unity.