Use meta_query w/Custom Fields

Hi guys,

I’m wanting to modify some of my GD queries using pre_get_posts and a custom field value but I realized the custom fields are stored in their own tables related to their CPT.

Here’s the code I have so far:

/*-------------------------------------------------------------------------------
	Show More Posts Per Page & Filter Out Sold Listings
-------------------------------------------------------------------------------*/
function show_more_posts($query) {
	if ( empty( $query->query_vars['suppress_filters'] ) ) {
		if( geodir_is_page('listing') || geodir_is_page('author') || geodir_is_page('search') ) {
			$query->set( 'posts_per_page', -1 );
			$query->set( 'meta_query', array(
				'relation' => 'OR',
				array(
					'key' => 'geodir_is_sold',
					'value' => 1,
					'compare' => '=',
					'type' => 'BINARY'
				),
				array(
					'key' => 'geodir_is_sold',
					'compare' => 'NOT EXISTS',
					'value'   => 'completely'
				)
			)
			);
		}
	}
	return $query;
}
add_filter( 'pre_get_posts' , 'show_more_posts' );

Do you guys know how I could modify the query in the way I’m try to?