Example on duplicating common template files inside a custom template, e.g. (moving the ALPHA-INDEX)

1. copy files (files mentioned below, are inside components\com_flexicontent folder):
  tmpl_common\listings_filter_form.php
  tmpl_common\listings_filter_form_body.php

inside your template folder:
  e.g. templates\blog-1\

2. edit file:
  templates\blog-1\category_items.php and change line:

include(JPATH_SITE.DS.'components'.DS.'com_flexicontent'.DS.'tmpl_common'.DS.'listings_filter_form.php');

to be:

include('listings_filter_form.php');

3. edit file:
  templates\blog-1\listings_filter_form.php

change line:

include(JPATH_SITE.DS.'components'.DS.'com_flexicontent'.DS.'tmpl_common'.DS.'listings_filter_form_body.php');

to be:

include('listings_filter_form_body.php');

4. edit file:
  templates\blog-1\listings_filter_form_body.php

find lines:

// Alpha-Index
if ($this->params->get('show_alpha', 1)) :
  echo $this->loadTemplate('alpha');
endif;

and move it to the file/place that you want:
e.g. move it at the top of
  templates\blog-1\category.php