you can try something like this:
/**
* Exclude current and static post/page from relationship field results
*/
// 1. Add the name=[NAME_OF_RELATIONSHIP_FIELD].
add_filter('acf/fields/relationship/query/name=my_relationship_field', 'exclude_id', 10, 3);
// 2. Add the $field and $post arguments.
function exclude_id ( $args, $field, $post ) {
//3. $post argument passed in from the query hook is the $post->ID.
$args['post__not_in'] = array( $post, 1994, 1999, 1979, 4201, 1989 );
//should exclude post you edit, and posts with id 1994, 1999, 1979, 4201, 1989
return $args;
}
