HI, As others have alluded to you if you are inspecting an element on a live page then you must have already navigated to that page and therefore its whereabouts must be known to you (although of course the page may be built with includes or php so you won't know where all fragments came from).
When you inspect an element then you get the css for that element and you can also see the html in that current page that the css refers to. It won't tell you where on your server that page is located but in most cases that would be pretty obvious from the url for most simple sites.
You may need to explain a little more about the problems you are having and maybe we can suggest something else.:)