livecanvas

The Purpose: allowing your users to search differently
Ajaxed search engines are all over the place ? literally. 
Whenever a large amount of items is available, be it houses for rent 
or computer spare parts, providing your users with a fast, structured, faceted search 
can be one thousand times more efficient, rather than letting your visitors sink into hundreds of web pages, 
hoping they?ll find what they need ? almost by chance. 
This tool does not replace or try to extend the build in textual search feature of WordPress; 
it aims to provide a quick bootstrap to an ajaxed search engine, demonstrating how easy it can be to turn 
your website into a powerful search tool, without installing a huge and bloated code.
It is easy to hack and to extend at your will. 
You can read here the original article about why <a href="http://www.dopewp.com/searchy/" rel="nofollow ugc">Searchy</a> was built.
<h3>Main Features</h3>
Let your users search combining different criterias: Filter by name, category, tag, or custom field (=1). 
Sort results by date, name or custom field (numeric)
<h3>Typical usage</h3>
Searchy is a customizable search engine composed of two elements: the search filters – typically a filters column, and the search results.
Use the searchy_filter shortcode or the built-in widget to show the filters column. 
Place the searchy_results shortcode in a WordPress page to show the sort bar and the search results. 
Of course those go in square brackets in a chosen Page. 
You can place them one after the other, having searchy_filter and searchy_results close, 
Or get fancy building your custom layout, placing some do_shortcode calls wherever you want.

Searchy

An AJAX Search Engine allowing different criterias for sorting and filtering your posts. Use via simple shortcodes and few settings.

Andrea Landonio

Taxonomy Filter is a simple and flexible plugin which allow users to filter hierarchical term taxonomies inside admin pages. If you need to simplify your tags and categories research on admin pages, this plugin will make it easier for you. It adds a custom input field (only for configured taxonomies) that you can use to filter a every taxonomy list.
Imagine having too many tags on your post admin page and having to lose so much time scrolling a long list of items or having to search for a tag with the classic browser search box. With “Taxonomy Filter” plugin you can search, choice and select tags in a very short time, a great gain!
In addition, you have to setup which taxonomies should have “Taxonomy Filter” activated. When you install and activate the plugin, an admin page is added on settings section. In this page are automatically listed all valid taxonomies, you have two options:
<ul>
<li>enable on post management pages (allow you to turn on/off filter field)</li>
<li>hide filter field if taxonomy is empty</li>
</ul>
You can also manage taxonomy filters into bulk edit section if you want to perform a quick edit.
If in your theme you have changed post columns using the ‘manage_edit-post_columns’ filter, you need to add another filter to apply the taxonomy filter bulk section. 
For example:
<pre><code>add_filter('manage_edit-post_columns', 'taxonomy_filter_manage_bulk_columns', 99, 1);
add_filter('manage_edit-<CUSTOM-TYPES>_columns', 'taxonomy_filter_manage_bulk_columns', 99, 1);
</code></pre>
It works only with hierarchical taxonomies (both default categories and <a href="https://codex.wordpress.org/Custom_Taxonomies" rel="nofollow ugc">custom taxonomies</a>).
When you enable a taxonomy filter, a section for choosing hidden taxonomy terms is displayed in user profile page and in term edit pages. In user profile page you can select (for each user) a list of taxonomy terms that are removed from hierarchical term taxonomies inside admin pages. 
By default, all taxonomy terms are visible in the hierarchical term taxonomies sections inside admin pages. You can choose only from max 2 nested levels but all the children of a hidden term are automatically removed from admin pages. Keep in mind that the hidden terms are not searchable and filterable. 
In edit term page you can select (for all users) if term should be removed (make hidden) from hierarchical term taxonomies inside admin pages.
<h4>Usage</h4>
<ol>
<li>Go to <code>WP-Admin -> Posts -> Add New</code>.</li>
<li>Find the input filter field on page sidebar.</li>
<li>Select tags filtering list.</li>
</ol>
Links: <a href="http://www.andrealandonio.it" rel="nofollow ugc">Author’s Site</a>

Taxonomy Filter

Taxonomy Filter is a plugin which allow users to filter hierarchical taxonomy terms inside admin pages and provides a way to hide terms for each user

Searchy vs Taxonomy Filter