Is it possible to view a "timeline" (history) for a selected file for like 50 commits? I mean changes made to this particular file and and view commits when they were made and users who changed them? I know Xcode got some powerful version control features, I just can not find this one.
What it sounds like you want is the "Blame View", if we were on the terminal you could write git blame <file-name>
to see the commit/time/and user for every single line of a particular file. In Xcode you can accomplish the same thing by activating the blame view. I've posted a picture to show you where the Blame View button resides. From there you should be all set.