Can a Druid 4/Barabrian 3 take Lesser Elemental Rage? The PRD states: "Elemental Rage, Lesser (Su): As a swift action, the barbarian can cause her melee attacks to deal an additional 1d6 points of energy damage (acid, cold, electricity, or fire) for 1 round. A barbarian must be at least 4th level to select this rage power. This power can only be used once per rage.". I read this as the Barbarian has to have 4 levels of Barbarian. One of my players took it with his character and he reads it as long as the character has 4 levels he can take it as a rage power.
Has to have 4 levels of Barbarian to select the power. Any time a class says that an ability requires the X to be Y levels, it means the character must have Y levels in X class. Druid levels are not Barbarian levels.