How using the Meta Box plugin, to filter posts by the value of a post type field?

I’m not familiar with the Meta Box plugin or it’s capabilities (and please note that third-party products are considered off-topic here!) – but regarding the question in the scope of core WordPress alone… For clarity’s sake, I envision the lessons_teacher meta-value to look similar to [[‘post_name’ => ‘john_smith’], [‘post_name’ => ‘jane_doe’]] SQL – and by … Read more