The Metadata Plugin provides a search extractor that will add each piece of metadata to the Confluence index.
If you are using the Comala Document Management for Server and Data Center app and creating metadata with the app set-metadata macro, these metadata values are only indexed by Confluence and appear in the Confluence search if the Comala Metadata app is installed.
If there is any query on the metadata extractor, please a note using our support portal or directly to support@comalatech.com