Create Programs custom post type and make relation between program and event

 First we create custom post type for programs so go to mu-plugins and open php file for custom post.

In university_post_types() copy event post type code and repeat this code inside function and rename the things.

In program custom post type code remove excerpt from supports and add icon dashicons-awards

After that go to dashboard create Math program with dummy text and publish and also go permalinks and update

Now this program single post use single.php but i want create dedicated page for this like single-program.php

Now copy code from single-event.php and paste in single-program.php

Now change metabox like below code

  <a class="metabox__blog-home-link" href="<?php echo get_post_type_archive_link('program'); ?>">

        <i class="fa fa-home" aria-hidden="true"></i> Programs Home

      </a>

and save

Now to display program archive we have to create archive-program.php page

and copy archive-event.php code and paste in archive-program.php page

And change title All Program also make empty while loop we will change design for program display.

add below code -> 

<ul class="link-list min-list">

    <?php

    while(have_posts()) {

        the_post(); ?>

    <li><a href="<?php the_permalink();?>"><?php the_title();  ?></a></li>

    <?php }

  echo paginate_links();

  ?>

  </ul>

and save now i want display program alphabet order so we have to write code in functions.php

Now go to university_adjust_queries() function and add below code 

  if(!is_admin() && is_post_type_archive('program') && $query->is_main_query()) {

    $query->set('orderby', 'title');

    $query->set('order', 'ASC');

    $query->set('posts_per_page', -1); //show all programs

  }

and save

Now make relation between Program and Events.

Go to Custom fields and create new give title Related Program and label Related Program(s)

field name related_programs field type Relationship

Filter by post type - program and Filters only Search

Location rules post type -> event

Now make save changes

Now edit any events you will see custom fields for Programs and add program and save change.