Multiple meta data inputs under one label

I am wanting one label but multiple data to be under the label. I also want to reference each input option individually so that I can query for specific meta data. Currently I have,

function custom_data_content( $post ) {
  wp_nonce_field( plugin_basename( __FILE__ ), 'custom_data_content_nonce' );
  $meta_values = get_post_meta($post->ID, 'file', true);
  echo '<label for="file"></label>';
  if($meta_values != '') {
    echo '<input type="text" id="fileName" name="fileName" placeholder="Enter the file name" value="' . $meta_values . '" /><br />';
  } else {
    echo '<input type="text" id="fileName" name="fileName" placeholder="Enter the file name" /><br />';
  }
  echo '<input type="text" id="fileSize" name="fileSize" placeholder="Enter the file size" /><br />';
  echo '<input type="text" id="version" name="version" placeholder="Enter the version" /><br />';
  echo '<input type="text" id="MD5" name="MD5" placeholder="Enter the MD5" />';
}

I have no idea how to reference each input using $meta_values. Can anyone help me?