JetEngine. Example of custom context to get some object by ID of the object provided in the query

query-object-context.php

<?php
/**
 * Slug of the context.
 * You can change it but please kepp a snake-case namin and latin letters
 */
$custom_context_slug = 'custom-object-by-id';

/**
 * Register context for the context dropdown
 */
add_filter( 'jet-engine/listings/allowed-context-list', function() use ( $custom_context_slug ) {
	// here you can change 'Custom Object by ID' in the way you need
	$context_list[ $custom_context_slug ] = 'Custom Object by ID';
	return $context_list;
} );

/**
 * Get the object for the you custom context.
 */
add_filter( 'jet-engine/listings/data/object-by-context/' . $custom_context_slug, function() use ( $custom_context_slug ) {

	$query_var = 'ID'; // Here you can set query var you need instead of 'ID'
	$id = ! empty( $_REQUEST[ $query_var ] ) ? absint( $_REQUEST[ $query_var ] ) : false;

	if ( ! $id ) {
		return false;
	}

	/**
	 * This is example for the post, but you can replace this part with getting any object you need.
	 */
	$object = get_post( $id );

	if ( ! $object ) {
		return false;
	}

	return $object;
} );