acf/fields/select/query/key=(field_key) │ filter-hook │ ACF 1.0

Usage

add_filter( 'acf/fields/select/query/key=(field_key)', 'wp_kama_acf_fields_select_query_key_field_filter', 10, 2 );

/**
 * Function for `acf/fields/select/query/key=(field_key)` filter-hook.
 * 
 * @param  $shortcut 
 * @param  $options  
 *
 * @return 
 */
function wp_kama_acf_fields_select_query_key_field_filter( $shortcut, $options ){
	// filter...
	return $shortcut;
}

$shortcut

-

$options

-

Where the hook is called

$shortcut = apply_filters( 'acf/fields/select/query/key=' . $options['field_key'], $shortcut, $options );

Where the hook is used in Advanced Custom Fields PRO

add_action( 'acf/fields/select/query/key=_acf_bidirectional_target', 'acf_build_bidirectional_relationship_field_target_args', 10, 2 );