Verb means to separate a whole into its parts and then look more closely at those parts

Analyze

Explanation:

This is the verb that best matches such description. When we analyze something, we tend to separate it into several different parts in order to make it more manageable. Moreover, we also look more closely at this parts. This ensures that we address the subject as fully as possible. It also enables us to make a careful study of the thing that we are looking at.