FilterAddExistingListExample.php

<?php

class MyPage extends Page {
  
  private static $many_many = array(
    "CoolPages" => "SiteTree"
  );
  
  function getCMSFields(){
	$fields->addFieldToTab(
		'Root.CoolPages',
		$grid = GridField::create(
			'CoolPages',
			'Cool Pages',
			$this->CoolPages(),
			$config = GridFieldConfig_RelationEditor::create()
		)
	);
	$gridFieldAddExistingAutocompleter = $config->getComponentsByType('GridFieldAddExistingAutocompleter')->first();
	$onlyPagesWithImages = SiteTree::get()->exclude(array("ImageID" => 0));
	$gridFieldAddExistingAutocompleter->setSearchList($onlyPagesWithImages);    
	return $fields;
  }

}