我一直在寻找你问题的相同答案，遇到了完全相同的问题，非常感谢你的深入研究。我在这里绝对是第一个提出这个补充的人！

尝试回答2）-我认为没有很好的理由排除它。我认为WordPress的分类术语与post和user实体相比，在功能上缺乏可悲之处（看看术语meta是如何在post和user meta之后出现的），我希望看到这种变化。

回答1）-我不知道这比您的解决方案好多少，但我提出的解决方法涉及通过get_terms_args 筛选，然后在客户端JS中手动插入选择下拉菜单+筛选按钮。下面是我的设置示例（修改为不使用我的特定类或常量），它通过某个术语元字段进行过滤：

PHP Logic

// @see https://developer.wordpress.org/reference/hooks/get_terms_args/
add_filter( \'get_terms_args\', \'taxonomy_filter\', 10, 2 );

function taxonomy_filter( $args, $taxonomies ) {
    global $pagenow;
    if ( \'edit-tags.php\' !== $pagenow || ! in_array( \'taxonomy-name\', $taxonomies, true ) ) { return $args; }

    // Sort by most recently added terms, instead of alphabetically
    $args[\'orderby\'] = \'term_id\';
    $args[\'order\'] = \'desc\';

    // Filter by term meta
    $meta_key = ( isset( $_GET[\'meta_key\'] ) ) ? sanitize_text_field( $_GET[\'meta_key\'] ) : null;
    $meta_value = ( isset( $_GET[\'meta_value\'] ) ) ? sanitize_text_field( $_GET[\'meta_value\'] ) : null;

    if ( \'meta-filter\' === $meta_key && $meta_value ) {
        $args[\'meta_key\'] = $meta_key;
        $args[\'meta_value\'] = $meta_value;
    }

    // Note: for more complex filtering, use the $args[\'meta_query\'] array.

    return $args;
}

Client-side jQuery logic

/**
 * Param helpers
 */

// Get params in a JS object
var params = {};
window.location.search.substr(1).split( \'&\' ).forEach(function(item) {
    params[ item.split( \'=\' )[0] ] = item.split( \'=\' )[1];
});

// Return param string based on the params object
function setParams() {
    var string = \'?\';

    for ( key in params ) {
        var value = params[ key ];
        string += key + \'=\' + value + \'&\';
    }

    return string.slice(0, -1); // Remove trailing &
}

/**
 * Add dropdown filters + functionality to term tables
 */

if ( \'taxonomy-name\' === params.taxonomy ) {
    // Create the dropdown menu & HTML
    $( document.querySelector( \'.tablenav .bulkactions\' ) ).after( \'\\
        <div class="alignleft actions"> \\
            <select id="js-filter-dropdown"> \\
                <option value="">Term Meta Filter</option> \\
                <option value="foo">Foo</option> \\
                <option value="bar">Bar</option> \\
                <option value="baz">Baz</option> \\
            </select> \\
            <button id="js-filter" class="button" type="button">Filter</button> \\
        </div> \\
    \' );

    // If we\'re already filtering the view, have the dropdown reflect that
    var value = decodeURIComponent( params.meta_value ).replace(/\\+/g, \' \');
    $( \'#js-filter-dropdown\' ).find( \'option[value="\' + value + \'"]\' ).prop( \'selected\', true );

    // Set up the button action - see taxonomy_filter() for server-side filtering
    $( \'#js-filter\' ).click(function() {
        var value = $( \'#js-filter-dropdown\' ).val();

        if ( value ) {
            params.meta_key = \'meta-filter\';
            params.meta_value = encodeURIComponent( value );
        } else {
            delete params.meta_key;
            delete params.meta_value;
        }

        window.location.search = setParams();
    });
}

Screenshot of the Filtering UI

Screenshot of the filtered table

快速复习课程，看来我们可以劫持bulk_actions-{$this->screen->id} 过滤器，在桌面添加额外的下拉列表。

Example

对于类别分类：

add_filter( \'bulk_actions-edit-category\', function( $actions )
{
    echo \'<select name="foo" ><option value="bar">Bar</option></select>\';

    return $actions;
} );

$wp_list_table = _get_list_table(\'WP_Terms_List_Table\');

Update:

add_filter( \'manage_edit-category_columns\', function( $columns ) use ( &$wp_list_table )
{    
    // Include the WP_Terms_List_Table class
    require_once ( ABSPATH . \'wp-admin/includes/class-wp-terms-list-table.php\' );

    // Extend the WP_Terms_List_Table class
    class WPSE_Terms_List_Table extends WP_Terms_List_Table
    {
        // Override this method
        protected function extra_tablenav( $which )
        {
            echo \'<select name="foo" ><option value="bar">Bar</option></select>\';
        }
    } 
    // end class

    $obj = new WPSE_Terms_List_Table;
    $obj->prepare_items(); 

    // Let\'s clone it to the global object
    $wp_list_table = clone $obj;

    return $columns;
} );