How do I fix this issue with enemies providing experience?

The player can kill enemies to get xp. The problem is that if 2 enemies die at the same time it only gives xp for one of them.

For example: The enemy gives 2 xp if it dies and the player´s arrow hit 2 enemies at the same time which should give the player 4 xp in total, only 2 xp is given.

Can I make this work with a "for each" loop? And if so could someone put together a foolproof example in the event sheet and screenshot it for me?

I don't think this needs a screenshot. Just add "For each Enemy" above the trigger once, that should do the trick.