gatekeeper

nouns

someone who controls access to something
"there are too many gatekeepers between the field officers and the chief"
gatekeeper
is a type of (narrower)
a human being
"there was too much for one person to do"
individual, mortal, person, somebody, someone, soul
someone who guards an entrance
door guard, doorkeeper, doorman, gatekeeper, hall porter, ostiary, porter