How to Add schema.org for custom fields

Hi I’m trying to add custom fields as itemprop in Google Structured Data But unable to find local business itemprops in Geodirectory. I have created “cusines”, “amenities” and rest is default “Time”
Where to mark these custom fields as itemprop for schema.org. I found the code but not getting any clues.

do_action('geodir_article_open', 'details-page', 'post-' . get_the_ID(), get_post_class(), 'http://schema.org/LocalBusiness');

Thanks