If the chosen source would simultaneously deal damage to multiple permanents you control (like Pyroclasm could) or to you and at least one permanent you control (like Earthquake could), Harm’s Way will redirect just 2 of that damage. It won’t redirect the next 2 damage that would be dealt to each recipient. You choose which 2 damage is redirected. If you like, you can choose to redirect 1 damage that would be dealt by the chosen source to each of two different recipients.