Company::class, ]; private static $many_many = [ 'Companys' => Company::class, ]; public function getCMSFields() { $fields = parent::getCMSFields(); $fields->removeByName('CompanyID'); $fields->addFieldToTab('Root.Main', SearchableDropdownField::create( 'CompanyID', 'Company', Company::get() ) ->setLabelField('Name') ->setIsLazyLoaded(true) ); $fields->addFieldToTab('Root.Main', SearchableMultiDropdownField::create( 'Companys', 'Companys', Company::get() ) ->setLabelField('Name') ->setIsLazyLoaded(true) ); return $fields; } }