book-2.0.x-dev/migrations/d7_book.yml

# cspell:ignore plid
id: d7_book
label: Books
migration_tags:
  - Drupal 7
  - Content
source:
  plugin: book
process:
  nid: nid
  'book/bid': bid
  'book/weight': weight
  'book/pid':
    -
      plugin: skip_on_empty
      method: process
      source: plid
    -
      plugin: migration_lookup
      migration: d7_book
destination:
  plugin: book
migration_dependencies:
  required:
    - d7_node