gform_entry_meta

add_filter( 'gform_entry_meta', 'custom_entry_meta', 10, 2 );

add_filter( 'gform_entry_meta', 'custom_entry_meta', 10, 2 );
function custom_entry_meta( $entry_meta, $form_id ) {
	// data will be stored with the meta key named score
	// label - entry list will use Score as the column header
	// is_numeric - used when sorting the entry list, indicates whether the data should be treated as numeric when sorting
	// is_default_column - when set to true automatically adds the column to the entry list, without having to edit and add the column for display
	// update_entry_meta_callback - indicates what function to call to update the entry meta upon form submission or editing an entry
	$entry_meta['score'] = array(
		'label' => 'Score',
		'is_numeric' => true,
		'update_entry_meta_callback' => 'update_entry_meta',
		'is_default_column' => true
	);

	return $entry_meta;
}

function update_entry_meta( $key, $lead, $form ) {
	//update score
	$value = "5";
	return $value;
}

add_filter( 'gform_entry_meta', function ( $entry_meta, $form_id ) {
	$entry_meta['test'] = array(
		'label'                      => 'Test',
		'is_numeric'                 => false,
		'update_entry_meta_callback' => 'update_entry_meta_test',
		'is_default_column'          => false,
		'filter'                     => array(
			'key'       => 'test',
			'text'      => 'Test',
			'operators' => array(
				'is',
				'isnot',
			)
		),
	);

	return $entry_meta;
}, 10, 2 );

function update_entry_meta_test( $key, $entry, $form ){
	//update test
	$value = "thisisatest";
	return $value;
}

add_filter( 'gform_entry_meta', array( 'GFQuiz', 'entry_meta' ), 10, 2 );
public static function entry_meta( $entry_meta, $form_id ) {
	$form = RGFormsModel::get_form_meta( $form_id );
	$quiz_fields = GFCommon::get_fields_by_type( $form, array( 'quiz' ) );
	if ( false === empty( $quiz_fields ) ) {
		$entry_meta['gquiz_score'] = array(
			'label' => 'Quiz Score Total',
			'is_numeric' => true,
			'update_entry_meta_callback' => array( 'GFQuiz', 'update_entry_meta' )
		);
		$entry_meta['gquiz_grade'] = array(
			'label' => 'Quiz Grade',
			'is_numeric' => false,
			'update_entry_meta_callback' => array( 'GFQuiz', 'update_entry_meta' )
		);
		$entry_meta['gquiz_percent'] = array(
			'label' => 'Quiz Percentage',
			'is_numeric' => true,
			'update_entry_meta_callback' => array( 'GFQuiz', 'update_entry_meta' )
		);
		$entry_meta['gquiz_is_pass'] = array(
			'label' => 'Quiz Pass/Fail',
			'is_numeric' => false,
			'update_entry_meta_callback' => array( 'GFQuiz', 'update_entry_meta' )
		);
	}
	return $entry_meta;
}

public static function update_entry_meta( $key, $lead, $form ) {
	$value = "";
	$results = self::get_quiz_results( $form, $lead, false );
	if ( $key == "gquiz_score" ) {
		$value = $results["score"];
	} elseif ( $key == "gquiz_percent" ) {
		$value = $results["percent"];
	} elseif ( $key == "gquiz_grade" ) {
		$value = $results["grade"];
	} elseif ( $key == "gquiz_is_pass" ) {
		$value = $results["is_pass"] ? "1" : "0";
	}
	return $value;
}