A big part of being a business analyst is understanding the domain in which a change is happening.
That understanding is more than just knowledge, it is understanding how that knowledge fits together. Everything we learn is part of something bigger.
A business rule is part of a business process, a business rule is part of a business process, a business process fulfills a business requirement, a business requirement fulfills a high-level strategic goal.
For each detail we uncover as a business analyst we need to understand what all the bigger pictures are that the detail fits into. Each detail may fit into more than one bigger picture.