How to push to the opposite direction from a player ?

I want to make a spell that push away players from the caster. However, i dont want the players to be pushed in the same direction but to the opposit direction from the caster. As i'm bad at explaining, i made a really fast drawing (and it's not the best one but we still can understand what i mean) :

Here is the drawing : https://gfycat.com/PassionateNarrowCod