Decision making is a function of the mind. All sentient beings make decisions all over the universe.
The thought moment responsible for the decision making arises due to causes. It is impermanent and non-self. Decision making brings about results. This is what we call Karma and Vipaaka for unenlightened beings.
Decision making in and of itself cannot create results. For example, you can decide to raise your hand right now. But that decision will not lead to raising of the hand if the hand is paralysed. You can decide to look at something. But that decision will not lead to seeing if the eyes are blind or if there is no light.
"Do you believe that there is a higher power or other dimensions...?" : conceptually speaking, there are higher powers all around you. Your employer maybe able to make decisions that affect many compared to what you can do. The president of your country can be considered a higher power as his decisions can affect so many. When you are a kid, your parents, teachers are usually higher powers. A policeman can be a higher power. A judge can be a higher power. Similarly, there could be beings who are more advanced than humans. Their decisions can possibly affect many as well. But this is all conceptual reality. Conceptual reality does not reflect what is really happening here and now.
Even you and I can decide what should happen in the world. But it will not lead to the intended result if the causes are not present for that result to arise. This is true for humans and any other being in the universe.