Problem: I would like to create a dictionary-style site where each definition is a post in a custom post type. On the single definition page, I would like to show links to related definitions.
Solution: Use a custom taxonomy instead of a custom field. Create a term for each definition. Make sure the slug of the term matches the slug of each definition post.
Think of this taxonomy as "Where I want this Definition to appear as a related Definition". If you want to show Definition B and Definition C as related terms on the Definition A single post page, you must edit Definition B and Definition C. In both of these Definitions, you must select the term that matches Definition A in your custom taxonomy.
The relationships you define in each Definition only work in one direction, so if you want to show Definition A as a related term on the Definition B page, you must edit Definition A and select the term that matches Definition B.
Next, create a View of Definitions. Filter this View by your custom taxonomy, and select the option to supply a taxonomy term by shortcode URL. In this example, the shortcode parameter is wpvdefinitionrelationship. Place this View on your Definition Content Template or Layout. Use the [wpv-post-slug] shortcode to supply the relationship taxonomy term value:
[wpv-view name="related-definitions-view" wpvdefinitionrelationship="[wpv-post-slug]"]
This only works if the Taxonomy Term slug matches the Definition slug, as mentioned earlier.
Relevant Documentation:
https://toolset.com/documentation/user-guides/views-shortcodes/
https://toolset.com/documentation/user-guides/passing-arguments-to-views/
https://toolset.com/documentation/user-guides/front-page-filters/
