Matches nested tags such as [foo attr="data" loose ][foo]inner content[bar invisible="true"/][/foo][bar]lalala[/bar][/foo][foo]love[/foo] correctly. Simply recall on element->inner_content for recursive processing.

regex_nested.php

<?php
function regex_nested( $content ) {
  	$pattern = "/\[(?P<type>[^\]\s]+)(?P<props>[^\]]*?)((?P<tagclose>\s*\/\])|".
		"(\](?P<inner>([^\[]*|\<\!\-\-.*?\-\-\>|(?R))*)\[\/\\1\s*\]))/sm";
		if ( !preg_match_all($pattern, $content, $matches, PREG_OFFSET_CAPTURE) )
			return $content;
  
  	$elements = array();
  	foreach ( $matches[0] as $key => $match ) {
  		array_push( $elements, (object)array(
  			'node' => $match[0],
  			'type' => $matches['type'][$key][0],
  			'attributes_raw' => !empty( $matches['props'][$key][0] ) ? $matches['props'][$key][0] : '',
  			'attributes' => array(),
  			'no_inner' => (boolean)($matches['tagclose'][$key][1] > -1),
  			'inner_content' => !empty( $matches['inner'][$key][0] ) ? $matches['inner'][$key][0] : ''
  		) );
      
	return $elements;
}
?>