Wordpress Remove Parent Category From Permalink

The easiest way to remove parent category from permalink only if it has a child category is to include the below code in your theme's functions.php file

[php]

// Remove category base
add_filter('category_link', 'no_category_parents',1000,2);
function no_category_parents($catlink, $category_id) {
$category = &get_category( $category_id );
if ( is_wp_error( $category ) )
return $category;
$category_nicename = $category->slug;

$catlink = trailingslashit(get_option( 'home' )) . user_trailingslashit( $category_nicename, 'category' );
return $catlink;
}

// Add our custom category rewrite rules
add_filter('category_rewrite_rules', 'no_category_parents_rewrite_rules');
function no_category_parents_rewrite_rules($category_rewrite) {
//print_r($category_rewrite); // For Debugging

$category_rewrite=array();
$categories=get_categories(array('hide_empty'=>false));
foreach($categories as $category) {
$category_nicename = $category->slug;
$category_rewrite['('.$category_nicename.')/(?:feed/)?(feed|rdf|rss|rss2|atom)/?$'] = 'index.php?category_name=$matches[1]&feed=$matches[2]';
$category_rewrite['('.$category_nicename.')/page/?([0-9]{1,})/?$'] = 'index.php?category_name=$matches[1]&paged=$matches[2]';
$category_rewrite['('.$category_nicename.')/?$'] = 'index.php?category_name=$matches[1]';
}
// Redirect support from Old Category Base
global $wp_rewrite;
$old_base = $wp_rewrite->get_category_permastruct();
$old_base = str_replace( '%category%', '(.+)', $old_base );
$old_base = trim($old_base, '/');
$category_rewrite[$old_base.'$'] = 'index.php?category_redirect=$matches[1]';

//print_r($category_rewrite); // For Debugging
return $category_rewrite;
}

// Add 'category_redirect' query variable
add_filter('query_vars', 'no_category_parents_query_vars');
function no_category_parents_query_vars($public_query_vars) {
$public_query_vars[] = 'category_redirect';
return $public_query_vars;
}
// Redirect if 'category_redirect' is set
add_filter('request', 'no_category_parents_request');
function no_category_parents_request($query_vars) {
//print_r($query_vars); // For Debugging
if(isset($query_vars['category_redirect'])) {
$catlink = trailingslashit(get_option( 'home' )) . user_trailingslashit( $query_vars['category_redirect'], 'category' );
status_header(301);
header("Location: $catlink");
exit();
}
return $query_vars;
}

[/php]