As I have stated, you need to use the current post’s ID and then return the desired meta value for the given key. This must then be passed to a meta_query.
Just a tip, instead of using the unreliable $post global, use the query object saved in $wp_the_query, this will be reliable in 99.99% of the time to return the single post object on a single post page
$post = sanitize_post( $GLOBALS['wp_the_query']->get_queried_object();
To get the meta value of then, you can do
$key = 'meta_bedroom';
$same_beds = get_post_meta(
$post->ID,
$key,
true
);
Then we need to check if we have a value, and then append our meta_query
if ( $same_beds ) {
$properties['meta_query'] = [
'key' => $key,
'value' => $same_beds
];
}