Custom PayPal Adaptive Payments args

functions.php

<?php
/**
 * Custom PayPal Adaptive Payments args.
 *
 * @param array $args
 * @param WC_Order $order
 * @return array
 */
function custom_woocommerce_paypal_ap_payment_args( $args, $order ) {
	$args['receiverList'] = array(
		'receiver' => array(
			array(
				'amount' => '40.00',
				'email'  => '[email protected]',
				// 'primary' => 'true' // use this only for Chained Payment.
			)
		),
		'receiver' => array(
			array(
				'amount' => '15.00',
				'email'  => '[email protected]'
			)
		),
		'receiver' => array(
			array(
				'amount' => '60.00',
				'email'  => '[email protected]'
			)
		)
	);

	return $args;
}

add_filter( 'woocommerce_paypal_ap_payment_args', 'custom_woocommerce_paypal_ap_payment_args', 10, 2 );

When is this filter triggered? Is there a way to set the receivers on product creation?

Neovea is correct. The example code displayed here is not valid. It is setting the same key 'receiver' multiple times on the same array, so only the last one will ever be recorded. I'm sure his fork addressed this. This page should be updated to avoid confusion.

If you get only last amount than try this code
EX:

$receivers => array(
array(
'amount'=>reviever amount FIRST here,
'email'=> reviever paypal FIRST email here here
),
array(
'amount'=>reviever amount SECOND here,
'email'=> reviever paypal SECOND email here here
),
array(
'amount'=>reviever amount THIRD here,
'email'=> reviever paypal THIRD email here here
)
);

$args['receiverList'] = array(
    'receiver' => array($receivers)
);
return $args;