$content = 'http://www.taobao.com  http://mai.taobao.com http://xx.uz.taobao.com http://yy.uz.taobao.com ';

preg_match_all('/(https?:\/\/[^.]+\.uz\.taobao\.com)/i', $content, $match);
print_r($match[1]);

so easy.

<?php

$content = 'http://www.taobao.com  http://mai.taobao.com http://xx.uz.taobao.com http://yy.uz.taobao.com ';
$pattern = '/http:\/\/[^\/]*?\.uz\.taobao\.com/is';

preg_match_all($pattern, $content, $result);
var_dump($result);

// output
array(1) {
  [0] =>
  array(2) {
    [0] =>
    string(23) "http://xx.uz.taobao.com"
    [1] =>
    string(23) "http://yy.uz.taobao.com"
  }
}

$content = '<a href="http://www.taobao.com"> sdfasdfasfas sdfsfasf http://mai.taobao.com http://xx.uz.taobao.com http://yy.uz.taobao.com ';
$urls = explode('http://', $content);
array_shift($urls);
$res = [];
foreach($urls as &$url) {
    $item = explode('taobao.com', $url);
    $url = "http://{$item[0]}taobao.com";
    if(preg_match('/uz\.taobao\.com/', $url))
        $res[] = $url;
}
print_r($res);
//Array ( [0] => http://xx.uz.taobao.com [1] => http://yy.uz.taobao.com )

$content = '<a href="http://www.taobao.com"> sdfasdfasfas sdfsfasf http://mai.taobao.com http://xx.uz.taobao.com http://yy.uz.taobao.com ';
preg_match_all('/(http[^taobao]*?uz\.taobao\.com)/i', $content, $match);
print_r($match[1]);
//Array ( [0] => http://xx.uz.taobao.com [1] => http://yy.uz.taobao.com )

另有一个小建议是：一步分成两步，先把URL分拆，再对每个URL做匹配。这样可以增强语义的直观性。