>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #3551338. --> Reported by: [mdranove](https://www.drupal.org/user/3695874) Related to !170 !169 >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p>As part of <a href="https://www.drupal.org/project/book/issues/3537360" title="Merge the functionality of Custom Book Block to Book 3">Merge the functionality of Custom Book Block to Book 3</a>, create a configuration on the book navigation block to choose the starting level.</p> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <p>Merge the code from custom book block's ExpandBookManager.php and CustomBookNavigationBlock.php into this module's bookTreeAllData and bookNavigationBlock.</p> <h3 id="summary-remaining-tasks">Remaining tasks</h3> <p>Test coverage<br> Update hook</p> <h3 id="summary-ui-changes">User interface changes</h3> <p>Screenshots should go here</p> <h3 id="summary-api-changes">API changes</h3> <p>NA</p> <h3 id="summary-data-model-changes">Data model changes</h3> <p>NA</p> > Related issue: [Issue #3537360](https://www.drupal.org/node/3537360)