gistfile1.php

<?php
$competitions = array(
	0 => array(
		'id' => '12345',
		'result_scope' => array(
			'competition-status' => 'scheduled',
		),
	),
	1 => array(
		'id' => '32451',
		'result_scope' => array(
			'competition-status' => 'in-progress',
		),
	),
	2 => array(
		'id' => '21453',
		'result_scope' => array(
			'competition-status' => 'in-progress',
		),
	),
);


$competition_status = 'in-progress';

foreach($competitions as $index => $competition){
	if($competition['result_scope']['competition-status'] != $competition_status)
		unset($competitions[$index]);
}
$competitions = array_values($competitions);
echo "<pre>"; print_r ($competitions); die("</pre>");