Property Hive - Elementor - Show only properties of a custom department with a parent/child relation

snippet.php

add_action(
	'elementor/query/plotspropertyquery',
	'elementor_query_plots'
);

function elementor_query_plots( $query ) {

	$current_property_id = get_queried_object_id();

	if ( ! $current_property_id ) {
		return;
	}

	$reference_number = get_post_meta(
		$current_property_id,
		'_reference_number',
		true
	);

	// Don't return anything if the current property
	// doesn't have a reference number.
	if ( empty( $reference_number ) ) {
		$query->set( 'post__in', array( 0 ) );
		return;
	}

	$query->set( 'post_type', 'property' );

	$query->set( 'meta_query', array(
		'relation' => 'AND',

		// Only properties in the Plots department.
		array(
			'key'     => '_department',
			'value'   => 'plots',
			'compare' => '=',
		),

		// Parent development must match the current
		// property's reference number.
		array(
			'key'     => '_parent_development',
			'value'   => $reference_number,
			'compare' => '=',
		),
	) );
}