There could be a number of reasons as to why this may be useful, my reason being is the quick launch navigation as it is, is rather packed and therefore trying to use this functionality requires a lot of scrolling down every time. Fortunately you can place some script on the page to push the Metadata navigation to the top of the quick launch, code courtesy of Steve Borgwordt.

Within your list, edit the page and insert a Script editor webpart (Found in Media and Content under the Categories section). Add the following code below.

<script src=”https://code.jquery.com/jquery-latest.min.js” type=”text/javascript”></script>

<script>

$(document).ready(function () {

$(‘.ms-tv-box’).remove().prependTo($(‘.ms-core-sideNavBox-removeLeftMargin’));

});

</script>

If you are unable to view the Metadata navigation settings, check the site features to confirm the ‘Metadata Navigation and Filtering’ feature is activated.