This was tough but a post on the web made it possible.
If looking at a node I want to find all other nodes related via a like tag.
So if node90 has tag test then when you are looking at it you should see node100 if it also has tag test.
Here is the php code in the argument Taxonomy Term ID

$node = node_load(arg(1));
if($node){
foreach($node->taxonomy as $term){ 
 /* test if in tag vocab */
 if($term->vid == '2'){
 $status = 'TRUE';
 $terms[] = $term->tid; 
 }
}
 if($status == 'TRUE'){
  return implode('+', $terms);
 } else { return; }
} else { 
return; }

Here is an export of the view

$view = new view;
$view->name = 'relatedbytag';
$view->description = 'related kb items by tag';
$view->tag = 'KB';
$view->view_php = '';
$view->base_table = 'node';
$view->is_cacheable = FALSE;
$view->api_version = 3.0-alpha1;
$view->disabled = FALSE; /* Edit this to true to make a default view disabled initially */

/* Display: Defaults */
$handler = $view->new_display('default', 'Defaults', 'default');
$handler->display->display_options['access']['type'] = 'none';
$handler->display->display_options['cache']['type'] = 'none';
$handler->display->display_options['exposed_form']['type'] = 'basic';
$handler->display->display_options['pager']['type'] = 'full';
$handler->display->display_options['style_plugin'] = 'default';
$handler->display->display_options['row_plugin'] = 'fields';
/* Field: Node: Title */
$handler->display->display_options['fields']['title']['id'] = 'title';
$handler->display->display_options['fields']['title']['table'] = 'node';
$handler->display->display_options['fields']['title']['field'] = 'title';
$handler->display->display_options['fields']['title']['label'] = '';
$handler->display->display_options['fields']['title']['alter']['alter_text'] = 0;
$handler->display->display_options['fields']['title']['alter']['make_link'] = 0;
$handler->display->display_options['fields']['title']['alter']['trim'] = 0;
$handler->display->display_options['fields']['title']['alter']['word_boundary'] = 1;
$handler->display->display_options['fields']['title']['alter']['ellipsis'] = 1;
$handler->display->display_options['fields']['title']['alter']['strip_tags'] = 0;
$handler->display->display_options['fields']['title']['alter']['html'] = 0;
$handler->display->display_options['fields']['title']['hide_empty'] = 0;
$handler->display->display_options['fields']['title']['empty_zero'] = 0;
$handler->display->display_options['fields']['title']['link_to_node'] = 1;
/* Argument: Taxonomy: Term ID */
$handler->display->display_options['arguments']['tid']['id'] = 'tid';
$handler->display->display_options['arguments']['tid']['table'] = 'term_node';
$handler->display->display_options['arguments']['tid']['field'] = 'tid';
$handler->display->display_options['arguments']['tid']['default_action'] = 'default';
$handler->display->display_options['arguments']['tid']['style_plugin'] = 'default_summary';
$handler->display->display_options['arguments']['tid']['default_argument_type'] = 'php';
$handler->display->display_options['arguments']['tid']['default_argument_options']['code'] = '$node = node_load(arg(1));
if($node){
foreach($node->taxonomy as $term){ 
 /* test if in tag vocab */
 if($term->vid == \'2\'){
 $status = \'TRUE\';
 $terms[] = $term->tid; 
 }
}
 if($status == \'TRUE\'){
  return implode(\'+\', $terms);
 } else { return; }
} else { 
return; }';
$handler->display->display_options['arguments']['tid']['break_phrase'] = 1;
$handler->display->display_options['arguments']['tid']['add_table'] = 0;
$handler->display->display_options['arguments']['tid']['require_value'] = 0;
$handler->display->display_options['arguments']['tid']['reduce_duplicates'] = 1;
$handler->display->display_options['arguments']['tid']['set_breadcrumb'] = 0;
/* Argument: Node: Nid */
$handler->display->display_options['arguments']['nid']['id'] = 'nid';
$handler->display->display_options['arguments']['nid']['table'] = 'node';
$handler->display->display_options['arguments']['nid']['field'] = 'nid';
$handler->display->display_options['arguments']['nid']['default_action'] = 'default';
$handler->display->display_options['arguments']['nid']['style_plugin'] = 'default_summary';
$handler->display->display_options['arguments']['nid']['default_argument_type'] = 'node';
$handler->display->display_options['arguments']['nid']['break_phrase'] = 0;
$handler->display->display_options['arguments']['nid']['not'] = 1;
/* Filter: Node: Type */
$handler->display->display_options['filters']['type']['id'] = 'type';
$handler->display->display_options['filters']['type']['table'] = 'node';
$handler->display->display_options['filters']['type']['field'] = 'type';
$handler->display->display_options['filters']['type']['value'] = array(
  'knowledgebase' => 'knowledgebase',
);
$handler->display->display_options['filters']['type']['expose']['operator'] = FALSE;

/* Display: Block */
$handler = $view->new_display('block', 'Block', 'block_1');
$handler->display->display_options['block_description'] = 'Related By Tag v2';