Does using Meditation to exhaust a friendly unit on DreamingTree trigger the battlefield ability to draw +3 cards total?

Ruling: No, Meditation does not trigger DreamingTree's battlefield ability. You only draw the +1 card from Meditation itself.

Nuances:

• Meditation exhausts a unit as a cost of playing the spell, not as a target or chosen unit
• DreamingTree requires choosing/targeting a unit to trigger its ability
• Meditation does not choose a unit, so it cannot trigger DreamingTree