The "File History" feature allows you to inspect how a single file evolved in detail - by listing only those commits in which the file was changed.
Selecting a File in Your Working Copy
One way to access a single file's commit history is through Tower's Working Copy view.
If the file in question isn't currently modified, remember to have Tower display all of your project's files (not just the modified ones) via the "View" main menu.
Simply right-click the file and choose.