Hey there.
You’re talking about having the functions loaded into your editor?
If so then many code editors can do that kind of thing. I use Coda for example and this works for me. You can install a WP syntax addon:
https://panic.com/coda/plugins.php
Or are you asking if you locate an issue visually on a theme can you then locate the code quickly?
If so then yeah, if you locate the issue is with a div you could search for the class/id pertaining to the div. If you use tools like Chrome Developer or FireBug this will let you easily see where the CSS comes from. They also have a number of other handy features, if you poke around YouTube there are a bunch of tutorials on these tools.
If this isn’t what you mean then please clarify further. ??
Hope this helps.
Take care.