If you're trying to find a define that is in versioncommon.h across the source, you look for it using STRG + F (Ctrl + F). Make sure to CheckMark "Current project" while having a project open. You'll need to check each project separately sometimes.
There are programs out there that help with the coloring of codes and finding references across the whole project as well, making it much more simpler to add your own creations.