How to access another child class from parent in JQuery? - html

Question

I have my markup looks like:
<div class="col-md-12 mainDiv">
<div class="rowDiv"> <!--first row starts-->
<div class="a1">
<div class="form-group">
<div class="dropdown-container-skills">
<select class="dropdown-skills">
<option>Select Any</option>
<option value="S1">Skill 1</option>
<option value="S2">Skill 2</option>
<option value="S3">Skill 3</option>
</select>
</div>
</div>
</div>
<div class="a1">
<div class="form-group">
<div class="dropdown-container-topics">
<select class="dropdown-topics">
<option>Select Any</option>
<option value="T1">Topic 1</option>
<option value="T2">Topic 2</option>
<option value="T3">Topic 3</option>
</select>
</div>
</div>
</div>
</div><!--first row ends-->
<div class="rowDiv"> <!--second row starts-->
<div class="a1">
<div class="form-group">
<div class="dropdown-container-skills">
<select class="dropdown-skills">
<option>Select Any</option>
<option value="S1">Skill 1</option>
<option value="S2">Skill 2</option>
<option value="S3">Skill 3</option>
</select>
</div>
</div>
</div>
<div class="a1">
<div class="form-group">
<div class="dropdown-container-topics">
<select class="dropdown-topics">
<option>Select Any</option>
<option value="T1">Topic 1</option>
<option value="T2">Topic 2</option>
<option value="T3">Topic 3</option>
</select>
</div>
</div>
</div>
</div><!--second row ends-->
</div>
I want something like when I select skill from first row it will update topics in the first row itself. Also when I select skill from second row it will update topics in second row and so on. I wrote the script for this as:
$('body').on('change', '.dropdown-skills', function(e) {
$.ajax({
type: "GET",
url: 'getTopics/' + $(this).val(),
dataType : "html",
success: function(response)
{
$(this).closest('.rowDiv').find('.dropdown-container-topics').html(response);
}
});
});
ie when I change class dropdown-skills it will get the topics as html from the controller function and it is then fed into class dropdown-container-topics of the current row.
But this is not working. How can it be done?