How do I get calls organized by phone number?
Generally speaking, please include hardware and software information, e.g. iPhone 4s, iOS 7.1.2, when asking questions as not all features are available in all models and iOS versions.

That said, I do not believe you have a choice, at least I don't on my iPhone in the Phone app, however I have an app on my MacBook Pro (also available for Windows) called iMazing that I can sort my call history by All and Contact and by Date, Contact, Duration and Number.  I can also export to Text or CSV files.

There may be a third-party iOS App that can do what you want right on the iPhone.  callLog may be a possibility.