It looks like it could be a misspelling of globalmetadata.dat (a common metadata file extension, e.g., in Valve's Steam or certain game engines). The extra dat at the end ( globalmetadatadat ) suggests a duplication.
In the world of Unity game modding and reverse engineering, global-metadata.dat decrypt globalmetadatadat
If you aren't comfortable with assembly code, several community tools can help: It looks like it could be a misspelling of globalmetadata