PHP - How Can I Find Out Parent (including) File Of Included File?

<?php 

// Get required login info
include "/path/to/login/info/file.php"; // Get required login info - changed for this post.

$db = new mysqli('localhost', $username, $password, $database); // Connect to DB using required login info
if($db->connect_errno > 0){
    die('Unable to connect to database [' . $db->connect_error . ']');
}

unset($username);// put these variables back to null
unset($password);// put these variables back to null
unset($database);// put these variables back to null


//query db
$sql = <<<SQL
    SELECT *
    FROM `ft_form_7`
	WHERE DATE(class_start_date) >= CURDATE()
	OR DATE(class_end_date) >= CURDATE()
	ORDER BY class_start_date ASC
SQL;

if(!$result = $db->query($sql)){ // if there is an error in running the query, show error message.
    die('There was an error running the query [' . $db->error . ']');
}

while($row = $result->fetch_assoc()){
	// Get start date information
	$start_date = $row['class_start_date']; // Get event_start_date for conversion and call it $start_date
	$start_date_formatted = date("l M d, Y", strtotime($start_date)); // Convert start_date 
	$end_date = $row['class_end_date']; // Get event_end_date for conversion and call it $start_date
	$end_date_formatted = date("M d, Y", strtotime($end_date)); // Convert start_date
	
	// Get time information.
	$start_time = $row['class_start_time']; // Get event_start_time for conversion and call it $start_time
	$start_time_formatted = date("h:i A", strtotime($start_time)); // Convert start_time 
	$end_time = $row['class_end_time']; // Get event_end_time for conversion and call it $end_time
	$end_time_formatted = date("h:i A", strtotime($end_time)); // Convert end_time 
	
	// echo information...
	    echo "<h2>" , $row['class_name'],"</h2>" ; // echo event name
	    echo "<p><strong>",$start_date_formatted; // echo the start date
		if (empty($start_time)) { echo ''; } else { echo " (", $start_time; } // echo start time
		if (empty($end_date)) { echo ''; } else { echo " -","<br />", $end_date_formatted; } // echo end date
		if (empty($end_time)) { echo ')'; } else { echo " - ", $end_time, ")"; } // echo end time
	// if there is no start time, echo nothing. (otherwise it seems to echo 4pm). If it does contain a time, echo the time.
	echo "</strong><br />";

	$chef = $row['Instructor'];
	global $chef;
	
	if ($chef != NULL) {
		require ('instructors.php'); }
	echo $row['class_description'], "<br />";
	echo "<strong>" , $row['type'], "&nbsp;-&nbsp;Cost: &#36;",$row['cost'] , " - #" , $row['course_number'] , "</strong><br />" , "</p>"; // echo class type and cost
}

$db->close();
$result->free();

?>

<?php

include "/path/to/login/info/file.php"; // Get required login info - changed for this post.

$db_instructors = new mysqli('localhost', $username, $password, $database); // Connect to DB using required login info
if($db_instructors->connect_errno > 0){
    die('Unable to connect to database [' . $db_instructors->connect_error . ']');
}

unset($username);// put these variables back to null
unset($password);// put these variables back to null
unset($database);// put these variables back to null

//query db
$sql_instructors = <<<SQL
    SELECT *
    FROM ft_form_8
    WHERE chef_name = '$chef'
SQL;

if(!$result_instructors = $db_instructors->query($sql_instructors)) { // if there is an error in running the query, show error message.
    die('There was an error running the query [' . $db_instructors->error . ']');
}

	while($row_instructors = $result_instructors->fetch_assoc()) {
	$chef_full_name = $row_instructors['chef_name'];
	$chef_id = $row_instructors['submission_id'];
	$full_bio = $row_instructors['full_bio'];
	echo "<a href=\"#\" class=\"clickme\">" , $chef_full_name , "</a>";
	echo "<div class=\"box\">";
	echo $full_bio , "</div>";
}


$db_instructors->close();
$result_instructors->free();

?>

<?php

include("../header.php");

?>

<?php include("header.php"); ?>
<?php include("content-lessons.html"); ?>
<?php include("footer.php"); ?>

<?php include("header.php"); ?>
<?php include("lesson1.html"); ?>
<?php include("footer.php"); ?>

if(isset($_GET['lesson1'])){
include('include/in-'.$_GET['lesson1.html']

$.post('poll.php', $(this).serialize(), function(data, status){

Fatal error: Uncaught --> Smarty: Unable to load template file 'test.tpl' <-- thrown in C:\xampp\htdocs\testing\includes\smarty\sysplugins\smarty_internal_templatebase.php on line 129

$smarty->testInstall();

Smarty Installation test...
Testing template directory...
C:\xampp\htdocs\testing\templates\frontend\default\tpl is OK.
Testing compile directory...
C:\xampp\htdocs\testing\templates_c\frontend is OK.
Testing plugins directory...
C:\xampp\htdocs\testing\includes\smarty\plugins is OK.
Testing cache directory...
C:\xampp\htdocs\testing\cache is OK.
Testing configs directory...
C:\xampp\htdocs\testing\configs is OK.
Testing sysplugin files...
... OK
Testing plugin files...
... OK
Tests complete.

var_dump($smarty->getTemplateDir());

htdocs
    -- testing
        -- incluses
            -- smarty
                plugins
                sysplugins
                Smarty.class.php
                SmartyBC.class.php
            -- configs
                configs.php
            -- db
                connect.php
                db.php
        -- configs
        -- cache
        -- templates
            -- frontend
                -- default
                    -- css
                    -- mages
                    -- js
                    -- tpl
                        test.tpl
            -- backend
        -- templates_c
            -- frontend
        index.php

<?php

ini_set('display_errors', 1);
ini_set('log_errors', 1);
ini_set('display_startup_errors', TRUE);
ini_set('error_log', dirname(__FILE__) . '/error_log.txt');
error_reporting(E_ALL);

ob_start();
session_start();

require 'includes/smarty/Smarty.class.php';
require 'includes/db/db.php';
require 'includes/configs/configs.php';

$page = isset($_GET['do']) ? $_GET['do'] : '';

switch($page){
	
	case 'home';
	include 'pages/home.php';
	break;
	
	default:
	include 'pages/test.php';
	break;
	
}

ob_flush();

?>

<?php

$smarty = new Smarty();
$smarty->compile_check = true;
$smarty->debugging = false;
$smarty->cache = 1;
$smarty->setTemplateDir('C:/xampp/htdocs/testing/templates/frontend/default/tpl');
$smarty->setCompileDir('C:/xampp/htdocs/testing/templates_c/frontend/default');
$smarty->setCacheDir('C:/xampp/htdocs/testing/cache');
$smarty->setConfigDir('C:/xampp/htdocs/testing/configs'); 

?>

<?php

//$success = 'Success Message';
//$error = 'Error Message';
$errors[] = 'Error one';
$errors[] = 'Error two';

$smarty = new Smarty;
//$smarty->assign('success', $success);
//$smarty->assign('error', $error);
$smarty->assign('errors', $errors);
$smarty->display('test.tpl');

?>

{if !empty($errors)}
<div id="errors">
{section name=i loop=$errors}
{$errors[i]}<br />
{/section}
</div>
{/if}