Of course, I do not know where you have gotten this phrase from, so I cannot tell you anything about its meaning in context. However, this is an English language idiom that is relatively common. If a person is “behind the wheel,” it means that they are driving an automobile. It could possibly be used figuratively, meaning that a person is in charge of something, but that is less common.
In English, we call the mechanism for steering a car the steering wheel because it is round and it is used to steer the car. We sometimes shorten this and simply call it “the wheel.” When you are driving the car, you have to sit behind the steering wheel. Therefore, if you are “behind the wheel,” it means that you are driving.
Since the person who is driving is in control of the car, we sometimes use this phrase to refer to being in charge more generally. For example, a new boss can take his or her place “behind the wheel” of the company. So, depending on the context in which you have seen this phrase, it either literally means that a person is driving a car or it means that they are in charge in some situation.
The meaning purely depends on the context in which it is used.In general 'Behind the wheel' refers to the one who makes the thing in consideration move 'forward' or in a 'progressive direction'.
The term came from motor vehicle concept, the one who runs the wheels ,the driver.
If it is a motor vehicle ,the one behind the wheel is the driver.
If it is an institution, the one behind the wheel is their head who takes them to new heights.
If it is family, then it can be the homemaker Mother or Father.
The meaning is contextual.