grumpy_intersect.php

<?php
$arr1 = array(
    'CustomerId' => NULL,
    'CsgHeaderInfo' => array( 
        'ConversationId' => NULL,
        'Region' => NULL,
        'RoutingArea' => "83513001",
    ),
    'SearchFilter' => array (
        'AccountId' => "8351300110000561",
        'CurrentItems' => "True",
        'HistoryItems' => "False",
        'LocationId' => NULL,
        'PendingItems' => "True",
    )
);

$arr2 = array (
    'method' => "GetCurrentServices",
    'CsgHeaderInfo' => array (
        'RoutingArea' => "83513001"
    ),
    'SearchFilter' => array(
        'AccountId' =>  "8351300110000561",
        'CurrentItems' => "True",
        'HistoryItems' => "False",
        'PendingItems' => "True"
    )
);

$realResult = array();
$result = array_uintersect_assoc($arr1, $arr2, function ($a1, $a2) use (&$realResult, $arr1) {
    if (!is_array($a1) && !is_array($a2)) {
        if ($a1 === $a2) {
            $realResult[array_search($a1, $arr1)] = $a1;
        }
    } else if (is_array($a1) && is_array($a2)) {
        foreach ($a1 as $k1 => $v1) {
            foreach ($a2 as $k2 => $v2) {
                if ($k1 == $k2 && $v1 == $v2) {
                    $realResult[array_search($a1, $arr1)][$k1] = $v1;
                }
            }
        }
    }
});

var_dump($realResult);

/*
array(2) {
  'CsgHeaderInfo' =>
  array(1) {
    'RoutingArea' =>
    string(8) "83513001"
  }
  'SearchFilter' =>
  array(4) {
    'AccountId' =>
    string(16) "8351300110000561"
    'CurrentItems' =>
    string(4) "True"
    'HistoryItems' =>
    string(5) "False"
    'PendingItems' =>
    string(4) "True"
  }
}
*/