Does Bellows Breath choose?

Yes, Bellows Breath involves choosing targets.

According to the card text and official rulings:

• Targeting: Bellows Breath instructs you to "Deal 1 to up to three units at the same location." This requires you to choose the units you wish to affect.
• Constraints: You must choose up to three distinct units at the same location. You cannot choose the same unit multiple times within a single instance of the spell.
• Repeat: If you pay the Repeat cost, you perform the effect a second time. You make a new set of choices for this second instance, which allows you to target the same unit again (resulting in a total of 2 damage to that unit) or choose entirely different units at the same or a different location.