You cannot do what you are attempting to do.
The issues
1) A post object fields stores the post ID of the post object selected
2) When set to allow multiple selections it stores a serialized array of post IDs
The first thing you need to do is know the post ID of the post object you want to filter by
'meta_query' => array(
array(
'key' => 'POST OBJECT FIELD NAME',
'value' => '"'.$post_id.'"'. // the post id that you are looking for
'compare' => 'LIKE'
)
)
