How to reverse engineer a section of a Drupal Page
Your question could use more specifics, but I think I understand what you are experiencing.

I've been there. If you cannot find it anywhere, a good bet is that it is part of the theme tpl pages. If you want to confirm this, you should go to the sites/all/themes/whatever-theme-you-are-using and search for files ending in .tpl.php, which are the files that control the theme you are currently using.

Frequently, any special effect or non-drupal configurable behaviour is likely inserted directly into these files. If your intention is to re-use whatever you are seeing at the top of the page, look for js (javascript) files: it is likely that dynamic pages are using some library, and that by googling the js filenames you can find a reference that might be useful.

At least, it has worked for me.