WordPress – manually relate a post to page(s)?

Unfortunately Post or object relationships is not possible in WordPress without doing a lot of extra work.

This feature is being actively discussed on this trac ticket any additional support for this would help our case of getting this included in core.

Your only options are:

  1. Use a plugin and modify it to fit your use case

  2. Map your posts to specially crafted taxonomies. (slow)

  3. Store relationships in postmeta. (very slow if you ever need to use that in a join statement)

  4. Create your own post2post table.

Further Reading: