Can you select a different battlefield with Bellows Breath if you repeat?

Yes. When you pay the Repeat cost for Bellows Breath, you can choose a different battlefield for the second instance. The two sets of targets are chosen independently (FAQ #1306, Rule 820.2.a).

The first instance deals 1 to up to three units at one location, and the second instance deals 1 to up to three units at a location — which can be the same battlefield or a completely different one (including an opponent's Base). Each instance still requires all its targets to be at the same location, but the two instances don't have to match.