How can I set “This block (override)” programmatically on a view's display
If you can't find a way to do this with the methods of Views API, you can try another approach by using the view entity (storage), which provides a more direct access to the display settings in an array.

Example

$view = \Drupal\views\Views::getView('myview');
$storage = $view-&gt;storage;
// add a new display
$storage-&gt;addDisplay('block', $new_title, $block_id);
// get the new display by reference
$new_display = &amp;$storage-&gt;getDisplay($block_id);
// copy the configuration and change the filter settings
$old_display = $storage-&gt;getDisplay($old_display_id);
$new_display = array_replace_recursive($old_display, $new_display);
$new_display['display_options']['filters']['nid']['value']['value'] = 123;

$storage-&gt;save();