This function returns queue priority group(s) by id.
jetapi backup -F getQueuePriority -D '_id=5d64857951d14773a519ec02' -O json
https://hostname.example.com:2087/cpsess##########/cgi/addons/jetbackup/api.cgi?function=getQueuePriority&_id=5d64857951d14773a519ec02