Not Brazil but my brother lived in a similar climate and showered before work, at lunch (everyone went home at lunch most days), and before bed.

He also had a massive stack of undergarments which included white t-shirts. He would sometimes change shirts more than he showered. For context he had to wear office attire but could wear Bermuda shorts.

Further context, we are swarthy Canadians that sweat when we eat a sandwich but he's was really thin/fit at the time. Still sweaty.

That's not common, no. 1 per day is the bare minimum, though, and 2 per day during the work week is usual.

Brazilian. I only take one shower/day unless it's very hot, then it's two. I don't think I ever took three showers/day. But bear in mind that the climate is very different depending on where you live in Brazil.