这是我的结构。。。。

状态1

CT1-1
     - Car_Model Post-CT1-1 (the posts of child)
     - Car_Model Post-CT1-2
CT2-1
     - Car_Model Post-CT2-2
CT3-1
     - Car_Model Post-CT3-1

CT1-2
CT2-2
CT3-2

CT1-3
CT2-3
CT3-3

州（分类学）

现在，在选择第2站时，我必须从分类学术语id查询帖子，而不是第3站中的制造商

 <!-- WORKING LOGIC Triple Drop Down Start -->

 <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" ></script>
 <script type="text/javascript">
$(function()
{
    $(\'#main_cat\').change(function()
    {
        var $mainCat=$(\'#main_cat\').val();

        // call ajax
        $("#sub_cat").empty();
        $("#manu_cat").empty();
        $.ajax
        (
            {
                url:"<?php bloginfo(\'wpurl\'); ?>/wp-admin/admin-ajax.php",     
                type:\'POST\',
                data:\'action=my_special_ajax_call&main_catid=\' + $mainCat,

                success:function(results)
                {
                    //  alert(results);
                    $("#sub_cat").removeAttr("disabled");       
                    $("#sub_cat").append(results);
                // it should be closed here an perform new ajax call not in success ok ? 
                    // Passing the sub_cat to the function for displaying 3rd drop down list
                    $(function()
                    {
                        $(\'#sub_cat\').change(function()
                        {
                            var $subCat=$(\'#sub_cat\').val();

                            // call ajax
                            $("#manu_cat").empty();
                            console.log($("#manu_cat"));
                            $.ajax
                            (
                                {
                                    url:"<?php bloginfo(\'wpurl\'); ?>/wp-admin/admin-ajax.php",     
                                    type:\'POST\',
                                    data:\'action=my_special_ajax_call&main_brand_id=\' + $subCat,

                                    success:function(results)
                                    {
                                        //  alert(results);
                                        $("#manu_cat").empty();
                                        $("#manu_cat").removeAttr("disabled");      
                                        $("#manu_cat").append(results); 
                                    }
                                }
                            );                                    
                        });
                    }); // function end for manufature jQuery
                }
            }
        );                                    
    });
});     
// for manufacturer logic paste here

 </script>
 <style type="text/css">
 #content{width:auto; height:400px; margin:50px;}
 </style>

 <form role="search" method="get" id="searchform" action="<?php echo get_option(\'siteurl\');?>/">
<div id="content">
    <?php 
        wp_dropdown_categories(\'show_count=0&selected=-1&hierarchical=1&depth=1&hide_empty=0&exclude=1&show_option_none=Select State&name=main_cat&taxonomy=state\');
    ?>
    <select name="sub_cat" id="sub_cat" disabled="disabled"></select>
    <select name="manu_cat" id="manu_cat" disabled="disabled"></select>

    <input type="submit" id="searchsubmit" value="Search" />        
</div>
</form> 


<!-- WORKING LOGIC Triple Drop Down End -->

Functions.php

function implement_ajax() {
if(isset($_POST[\'main_catid\']))
        {
        $categories=  get_categories(\'child_of=\'.$_POST[\'main_catid\'].\'&hide_empty=0\'.\'&taxonomy=state\');
//change the taxonomy state in your case
          foreach ($categories as $cat) {
            $option .= \'<option value="\'.$cat->term_id.\'">\';
            $option .= $cat->cat_name;
            //$option .= \' (\'.$cat->category_count.\')\';
            $option .= \'</option>\';
          }

          echo \'<option value="-1" selected="selected">Select City</option>\'.$option;
        die();
        } // end if

if(isset($_POST[\'main_brand_id\']))
        {
        $categories=  get_categories(\'&hide_empty=0\'.\'&taxonomy=manufacturer\');
//change the taxonomy manufacturer in your case
          foreach ($categories as $cat) {
            $options .= \'<option value="\'.$cat->term_id.\'">\';
            $options .= $cat->cat_name;
            //$option .= \' (\'.$cat->category_count.\')\';
            $options .= \'</option>\';
          }

          echo \'<option value="-1" selected="selected">Select Make</option>\'.$options;
        die();
        } // end if


}
add_action(\'wp_ajax_my_special_ajax_call\', \'implement_ajax\');
add_action(\'wp_ajax_nopriv_my_special_ajax_call\', \'implement_ajax\');//for users that are not logged in.

从这一行开始的逻辑if(isset($_POST[\'main_brand_id\'])) 必须更换，所以这里if(isset($_POST[\'main_brand_id\'])) 我必须通过分类法的term\\u id来检索帖子，请帮助我查询逻辑以检索相关帖子标题。希望有人能帮助我。。。。。。。。