To set up relationships between content on Drupal 8, follow these steps:
1. Enable the Entity Reference module in Drupal 8.
1. Create the content types that will have relationships. For example, create a “Book” content type.
1. Create the related content types. For example, create an “Author” content type.
1. Add a new field to the “Book” content type using the “Entity Reference” field type. Select the related content type (“Author”) as the reference target type.
1. Configure the field settings according to your needs. You can specify the number of values, the widget type, and the entity display settings.
1. Create content for the “Author” and “Book” content types.
1. Edit the “Book” content and select the related “Author” content using the “Entity Reference” field.
1. Save the “Book” content. You can now display the related “Author” content on the “Book” content page.
1. To display the related content on the “Author” content page, create a “View” that filters by the “Author” content type and uses the “Book” content type as the relationship. Then, add the View block to the “Author” content page.
By following these steps, you can set up relationships between content on Drupal 8 and display them in a meaningful way to your website visitors.