The style guidance for releases that include others encodes this metadata in the title by combining the titles with space-slash-space separators.

https://musicbrainz.org/doc/Style/Titles#Multiple_titles_.2F_Splits

Subsequent to the writing of this guidance, the Release Group Included In Release Group Relationship has become a better way to capture this metadata for releases so there is no reason to mangle the title to do so. The style guidance for such release titles should be rewritten to allow whatever title appears on the release and only fallback to the space-slash-space separator when the titles are presented with no alternative choice.