benknight

This is a simple plugin that was born out of working on several projects with sectional navigations. For example, consider the following common navigation tree structure:
<ul>
<li>Home</li>
<li>Item</li>
<li>About Us
<ul>
<li>Sub-item #1</li>
<li>Sub-item #2</li>
</ul>
</li>
<li>Item</li>
<li>Item</li>
</ul>
Then, whenever on the “About Us” page or any of its sub-items, it would output that peice of the navigation:
<ul>
<li>About Us
<ul>
<li>Sub-item #1</li>
<li>Sub-item #2</li>
</ul>
</li>
</ul>
This is particularly useful for websites that have a top horizontal navigation which shows top-level items and want to show a vertical subnavigation in the sidebar.
This plugin works by parsing the output of the <code>wp_nav_menu</code> function as XML and analyzing the CSS class hooks (current-menu-ancestor, current-menu-item, and current-menu-parent). Because it uses PHP’s SimpleXML library it therefore requires PHP 5+. It uses the theme’s registered menu locations.
This plugin also exposes the <code>section_subnav()</code> function for theme developers to use as a template tag to manually place a subnav inside the theme. Here is the usage:
<pre><code><?php

 section_subnav( array( // defaults
 'before_widget' => '<nav id="section-subnav" class="widget widget_section-subnav">',
 'after_widget' => "</nav>",
 'before_title' => '<h3 class="section-subnav-title widget-title">',
 'after_title' => '</h3>',
 'echo' => true
 ));

?>
</code></pre>
It returns false when there is no subnavigation.
This function also provides the <code>section_subnav_args</code> filter hook for writing less code and easier integration with other plugins and child themes.

Section Subnav

Adds a widget and template function for displaying subnavigation based on the current navigation state.

Max Chirkov

This plugin adds a widget into the Widgets dashboard that allows in a simple way, without writing any PHP code on your part, to create custom navigation in any sidebar pre-defined by your WP theme.
Features Include:
<ul>
<li>Flat and multi-level navigation hierarchy for existing pages and custom links.</li>
<li>Very flexible conditional appearance options (greatly expanded from before 2.0 version).</li>
<li>Out-of-the-box Suckerfish support.</li>
<li>Option to add navigation links with custom title, url and target attribute.</li>
<li>Unlimited number of navigation widgets.</li>
<li>Optional setting includes blog posts into the navigation selection list (only pages are available by default).</li>
<li>Support for custom drop-down menus CSS.</li>
</ul>
Recent Updates Log:
<ul>
<li>2.3.0 – Fixes deprecated class constructor.</li>
<li>2.2.0 – WP 3.8 Compatibility Update.</li>
<li>2.1.5 – Added compatibility with Advanced Text Widget PRO.</li>
<li>2.1.4 – Minor update with IE6 JS fix.</li>
<li>2.1.0 – WordPress 2.8 Compatible and newer versions ONLY.</li>
<li>2.0.10 – Fixed active links bug.</li>
<li>2.0.9 – Fixed array unserialization, which was being broken by non-US characters (i.e. German umlauts).</li>
<li>2.0.8 – There is a floating bug between serializing from JS into PHP and back – hopefully it’s fixed now.</li>
<li>2.0.7 – Fixed get_posts() 5 post limit; Added ON/OFF target attribute option to the Settings so it can be compliant with XHTML 1.0 Strict;</li>
<li>2.0.6 – Fixed an error when parsing serialized array: <code>Warning: array_key_exists(): on line 149</code>.</li>
<li>2.0.5 – Custom links with hyphens bug fixed.</li>
<li>2.0.4 – Removed unconditional suckerfish_e.js declaration.</li>
<li>2.0.3 – Changed navigation links to permalinks.</li>
<li>2.0.2 – Fixed links with apostrophes bug. (Link titles that had apostrophe in them weren’t saving.)</li>
</ul>
Conditional widget appearance is based on Daikos’ Text Widget by Rune Fjellheim.
<ul>
<li>Author: Max Chirkov</li>
<li>Author URI: <a href="http://SimpleRealtyTheme.com" title="Real Estate Themes & Plugins" rel="nofollow ugc">http://SimpleRealtyTheme.com</a></li>
<li>Copyright: Released under GNU GENERAL PUBLIC LICENSE</li>
</ul>
<h3>Video Demo</h3>
Check out this quick <a href="http://screencast.com/t/ztSVIGmARoY" title="Demo Video for Simple Sidebar Navigation" rel="nofollow ugc">video demonstration</a>.

Simple Sidebar Navigation

Easy way to create custom navigation in sidebars or other pre-defined areas. Conditional tags are included to specify pages where widgets appear.

Section Subnav vs Simple Sidebar Navigation