Split cart by shipping classes

functiuons.php

add_filter( 'woocommerce_cart_shipping_packages', 'split_cart_by_shipping_class' );

function split_cart_by_shipping_class($packages){
	
	$packages              	= array();
	
	$new_packages		=	array();
	
	// Group of shipping class
	$class_groups	=	array(
		'group1'	=>	array('heavy'),
		'group2'	=>	array('light'),		
	);	
	
	// Group cart items by shipping classes
	foreach ( WC()->cart->get_cart() as $item_key => $item ) {
		if ( $item['data']->needs_shipping() ) {
			
			$belongs_to_class_group	=	'none';
			
			$item_ship_class_id	=	$item['data']->get_shipping_class();
			
			if($item_ship_class_id){
				
				foreach($class_groups as $class_group_key	=>	$class_group){
					if(in_array($item_ship_class_id, $class_group)){				
						$belongs_to_class_group	=	$class_group_key;
						continue;
					}
				}
				
			}			
			
			$new_packages[$belongs_to_class_group][$item_key]	=	$item;
		}
	}
	
	// Add grouped items as packages 
	if(is_array($new_packages)){
		
		foreach($new_packages as $splitted_package_items){
			$packages[] = array(
				'contents'        => $splitted_package_items,
				'contents_cost'   => array_sum( wp_list_pluck( $splitted_package_items, 'line_total' ) ),
				'applied_coupons' => WC()->cart->get_applied_coupons(),
				'user'            => array(
					 'ID' => get_current_user_id(),
				),
				'destination'    => array(
					'country'    => WC()->customer->get_shipping_country(),
					'state'      => WC()->customer->get_shipping_state(),
					'postcode'   => WC()->customer->get_shipping_postcode(),
					'city'       => WC()->customer->get_shipping_city(),
					'address'    => WC()->customer->get_shipping_address(),
					'address_2'  => WC()->customer->get_shipping_address_2()
				)
			);
		}
	}
	
	return $packages;
}