New Post: how can i get all sibling ul

<h3 class="my-subject">a</h3>

<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>

<h3 class="my-subject">b</h3>

<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>
<ul class='ex'>....</ul>

how can i get just 6 siblings ul.ex  via  <h3 class="my-subject">a</h3>

and get next 6 ul via <h3 class="my-subject">b</h3> ?

 thanks 

HAP doesn't support xpath axis ? 

http://www.w3school.com.cn/xpath/xpath_axes.asp