As a business analyst we need to understand the whole and the parts.
We need to understand the details and how the details fit together to make the whole.
Once we understand the whole, we realize the whole is just a detail at the next level of abstraction. When we are presenting to the executive level we need to understand the details they deal with. Many times those details are what we consider the whole at a lower level.
A business analyst is always in the middle. The middle can be horizontal when we are the middle between business and the development team. The middle can also be vertical where we are the middle between business and the strategic level above business.
A business analyst needs to be able to talk about the forest or the trees or the eco-system or the effects between eco-systems.