Sauvegarde les lat / lng en postmeta. Utilise le champ ACF GoogleMaps de base, qui a pour nom "localisation"

fuji_save_latlng_meta.php

/**
 *	Save _lat _lng
 *
 **/
add_action( 'save_post', 'stl_store_meta_save' );
function stl_store_meta_save( $post_id )
{
	global $wpdb;
	
	$table = $wpdb->prefix .'geodatastore';
	
	if ( isset( $_POST['post_type'] ) && $_POST['post_type'] != 'store' )
        return;

	if( $localisation = get_post_meta( $post_id, 'localisation', true ) )
	{
		if( isset( $localisation['lat'] ) && isset( $localisation['lng'] ) )
		{
			add_post_meta( $post_id, '_lat',	sanitize_text_field( $localisation['lat'] ), true ) || update_post_meta( $post_id, '_lat',		sanitize_text_field( $localisation['lat'] ) );
			add_post_meta( $post_id, '_lng',	sanitize_text_field( $localisation['lng'] ), true ) || update_post_meta( $post_id, '_lng',		sanitize_text_field( $localisation['lng'] ) );
		}
	}
}