Is it possible to use a piece of the metadata to search for a song that has same metadata?

It depends on how you use that "piece of metadata" when searching. We support search using artist name, album name and track name. Then you will need to compare the returned metadata with what you have.
If what you like to achieve is to search with genre, mood and/or other metadata, then the answer will be no.
Give me an example of what you have in mind, and perhaps I can find something that can meet your needs.

I was planning to see if I could search based on mood. In which, you answered would be a no

That's correct. For the moment, the closet thing you can do is using Rhythm API and make a recommendation query with mood. You can add other filters like genre, artist, etc. which may help get the result you need. Hope this helps.

Can I search using mood with my collection of music, utilizing any of the Gracenote APIs?