While messing around in Bravely Second: End Layer, I stumbled on a couple of different things you can do to maximise your battle streak. Find out why this is important and how to do it in the video below!
I’ve been playing the Bravely Second demo a fair bit, and stumbled on a way to consistently achieve long battle streaks in the game.
In Bravely Second, managing to defeat your opponents in a single turn will allow you to take on another wave immediately after it if you so choose. Doing so adds a multiplier to the amount of money and experience you get at the end of the battle, alleviating the typical RPG a great deal.
Not only do you benefit from the multiplier, you get into battles faster. It’s an excellent mechanic, and my best streak thus far has seen me battle 24 waves of foes back-to-back and resulted in the reward you see in the image above. Bear in mind that this was against the weakest monsters in the game, and that only took me a few minutes.
So check out the video below to learn more! Thanks as always to New Game Plus.
Charlotte Buckingham 
Those streaks are a good way of leveling up your party and jobs.
go to the hot springs level where you get 3 BP at the start and also equip some dex modifiers and the venture badge to raise your brave attack rate, got a 40 battle streak there, on top of the 3.0 you get for battling you will get another 3.0 for getting at lest to 36.