Definition 1 of 2
But who you call Saar is a nuanced thing. It's a safe respectful designation without necessarily indicating hierarchy. If an implicit hierarchy is present, well and good, but when relative status is uncertain then Saar is a good bet.
It's not used in the familiar, like boss or hero. It may occasionally be used in reverse in an implicit hierarchy (i.e. high to low as opposed to the expected low to high) but this is terribly sarcastic and implies that some lowly bugger is about to get a tightslap if the sarcasm doesn't do the needful...
Ganapathi (to long awaited technician): "Ah, hello saar, yesterday only you were supposed to come..."
Radhakrisha: "Saaaar what to do saar, staff only is not available these days, so much demand, we have been asking for more people but they are not giving"
Ganapathi: "Ok ok, you please start the work, I will get some tea."
Ganapathi (to coolie): "Hello! Saar! Are you going to bring some tea for saar or chumma stand there smiling?"
Definition 2 of 2
Mr Gowda surprised and confused - " What Saar ... you are doing finaaa?"
Uncle Murthy walking on the road and Auto Driver Ranga stops by and says "Where goinguu saaar?"