When you play a card with a 'when you play me' effect that targets a battlefield (like Carnivorous Snapvine), can you target units at any battlefield?

Ruling: When you play me (WYPM) targets are not restricted by where you play the unit unless the WYPM says "here" in it. The ability may have its own targeting restrictions (like "at a battlefield"), but you can target any valid battlefield, not just the one where you played the unit.

Nuances:

• Hidden units with WYPM abilities are an exception: when played from hidden, those abilities must target units at the battlefield you played them from
• The WYPM ability itself may specify targeting restrictions (e.g., "at a battlefield") which must be followed