<?php
$events = [
    0 => [
        0 => [
            "rsvp_id" => 2,
            "event_id" => 237,
            "formatted_start_time" => 1443052800,
            "formatted_end_time" => 1443052800,
            "event_group_date" => "24 Sep, Thursday 2015"
        ],
        1 => [
            "rsvp_id" => null,
            "event_id" => 295,
            "formatted_start_time" => 1443070800,
            "formatted_end_time" => 1443070800,
            "event_group_date" =>" 24 Sep, Thursday 2015"
        ],
        2 => [
            "rsvp_id" => null,
            "event_id" => 294,
            "formatted_start_time" => 1443099600,
            "formatted_end_time" => 1443099600,
            "event_group_date" => "24 Sep, Thursday 2015"
        ],
        3 => [
            "rsvp_id" => 1,
            "event_id" => 330,
            "formatted_start_time" => 1443118800,
            "formatted_end_time" => 1443122400,
            "event_group_date" => "24 Sep, Thursday 2015"
        ]
    ],
    1 => [
        0 => [
            "rsvp_id" => 2,
            "event_id" => 332,
            "formatted_start_time" => 1443189600,
            "formatted_end_time" => 1443193200,
            "event_group_date" => "25 Sep, Friday 2015"
        ]
    ],
    2 => [
        0 => [
            "rsvp_id" => null,
            "event_id" => 239,
            "formatted_start_time" => 1443571200,
            "formatted_end_time" => 1443571200,
            "event_group_date" => "30 Sep, Wednesday 2015"
        ]
    ]
];

function process(array $events, $logged_in_user_id = 224) {
    $newEvents = [];

    foreach ($events as $i => $key) {
        if (is_array($key) && !isset($key["event_id"])) {
            foreach ($key as $index => $event) {
                if (is_array($event) && isset($event["event_id"])) {
                    $conditions = false;
                    if (!isset($event["rsvp_id"])) {
                        $aEventInvites = getInvites($event["event_id"]);

                        // try to match
                        foreach ($aEventInvites as $aeiKey => $aeiValue) {
                            if (is_array($aeiValue)) {
                                foreach ($aeiValue as $invites) {
                                    if (isset($invites["invited_user_id"]) && isset($invites["event_id"])) {
                                        if (
                                               $invites["invited_user_id"] == $logged_in_user_id
                                            && $invites["event_id"]        == $event["event_id"]
                                        ) {
                                            $conditions = true;
                                        }
                                    }
                                }
                            }
                        }
                    } else {
                        $conditions = true;
                    }

                    if ($conditions) {
                        $newEvents[] = $event;
                    }
                }
            }
        }
    }

    return $newEvents;
}

// Output of print_r($aEventInvites);
// dummy function since we just have sample data
function getInvites($eventId) {
	// do some cool stuff ...
	$result = [
		0 => 2,
		1 => [
			0 => [
				"invite_id"  => 698,
				"event_id"   => 332, // id passed to function
				"type_id"    => 0,
				"rsvp_id"    => 0,
				"user_id"    => 970,           // same id 970
				"invited_user_id" => 970    // same id 970
			],
			1 => [
				"invite_id" => 697,
				"event_id"  => 332, // id passed to function
				"type_id"   => 0,
				"rsvp_id"   => 0, 
				"user_id"   => 244,           // same id 244
				"invited_user_id" => 244    // same id 244
			]
		]
	];

    return $result;
}

// Conditions:
// - $events Elements with rsvp_id set
// - $events Elements getInvites($eventId)[invited_user_id] == $logged_in_user_id && getInvites($eventId)[event_id] == $event[event_id]

$events = process($events);
echo "<pre>";
var_dump($events);
echo "</pre>";

?>