Get all H3 between two H2 with jQuery

I'm building a dynamic summary generator with jQuery. I want to list all H2 and H3 on the page.

I did it for H2, this is my code:

EDIT: I just update my code, including H2 and H3 but there are few errors.

<div id="summary"></div>
<script>
var counter = 0;
$('h2').each(function() {
   counter++;
   $(this).attr("id", "title-" + counter);
   $('#summary').append('<a href="#title-' + counter + '" class="summary-link">' + $(this).text() + '</a>');
   //
   var counter_2 = 0;
   $('h2 ~ h3').each(function() {
     counter_2++;
     $(this).filter(function() {
        return $(this).nextAll('h2').length
     }).attr("id", "subtitle-" + counter_2);
     $('#summary').append('<a href="#subtitle-' + counter_2 + '" class="summary-link">' + $(this).text() + '</a>');
   });
});  
</script>

Blog post example:

<h2>Post title 1</h2>
<h3>Post subtitle 1</h3>
<h3>Post subtitle 2</h3>
<h2>Post title 2</h2>
<h3>Post subtitle 3</h3>
<h3>Post subtitle 4</h3>

My code results:

<h2 id="title-1">Post title 1</h2>
<h3 id="subtitle-1">Post subtitle 1</h3>
<h3 id="subtitle-2">Post subtitle 2</h3>
<h2 id="title-2">Post title 2</h2>
<h3 id="subtitle-3">Post subtitle 3</h3>
<h3 id="subtitle-4">Post subtitle 4</h3>

<a href="#title-1">Post title 1</a>
<a href="#subtitle-1">Post subtitle 1</a>
<a href="#subtitle-2">Post subtitle 2</a>
<a href="#subtitle-3">Post subtitle 3</a>
<a href="#subtitle-4">Post subtitle 4</a>
<a href="#title-2">Post title 2</a>
<a href="#subtitle-1">Post subtitle 1</a>
<a href="#subtitle-2">Post subtitle 2</a>
<a href="#subtitle-3">Post subtitle 3</a>
<a href="#subtitle-4">Post subtitle 4</a>

The expect results:

<h2 id="title-1">Post title 1</h2>
<h3 id="subtitle-1">Post subtitle 1</h3>
<h3 id="subtitle-2">Post subtitle 2</h3>
<h2 id="title-2">Post title 2</h2>
<h3 id="subtitle-3">Post subtitle 3</h3>
<h3 id="subtitle-4">Post subtitle 4</h3>

<a href="#title-1">Post title 1</a>
<a href="#subtitle-1">Post subtitle 1</a>
<a href="#subtitle-2">Post subtitle 2</a>
<a href="#title-2">Post title 2</a>
<a href="#subtitle-3">Post subtitle 3</a>
<a href="#subtitle-4">Post subtitle 4</a>

I don't know how I can get all H3 between two H2 so any help could be helpful.