There doesn’t appear to be an existing term that neatly fits. Here are some possibilities:
One-word terms:
Traumaraderie (portmanteau of “trauma” and “camaraderie”)
Two-word terms:
Stress bonding (a technique for bonding rabbits)
Trauma bonding (this is sometimes used to mean bonding between victims even though it also means bonding between victim and abuser in other contexts)
Trauma kinship
Survivor bond
Longer terms:
Friendship forged in fire
Shared trauma bonding
Mutual suffering solidarity
Camradery through adversity
Ah, I do see the LET function now but I still can’t find a reference to the Power Query editor.