In rub a dub what was the occupation of 3 men in bath?

The nursery rhyme "Rub-a-dub-dub" doesn't specify the occupations of the three men in the tub. It simply states:

"Rub-a-dub-dub,

Three men in a tub,

And who do you think they were?

The butcher, the baker, the candlestick maker."

So, the occupations are butcher, baker, and candlestick maker.