You must create a different search form for your post type, so that search results can be displayed according to post type.
You can add this to your search form
<input type="hidden" name="post_type" value="meetup_groups">
Example :
<form method="get" id="my-custom-searchform" action="<?php echo esc_url(home_url( "https://wordpress.stackexchange.com/" )); ?>">
<input type="text" value="<?php the_search_query(); ?>" name="s" id="s" placeholder="<?php echo esc_attr__( 'Search ...', 'text-domain' ); ?>" />
<button type="submit"><?php echo esc_html__('Search','text-domain'); ?></button>
<input type ="hidden" name="post_type" value="meetup_groups">
</form>
You also have to change the file search.php
To display as you see fit.
You must create a file that contains something like this to display the post type search.
For example I make a meetup-groups.php file with the following code.
<div class="meetup-groups">
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<!-- do stuff -->
<a href="https://wordpress.stackexchange.com/questions/351654/<?php echo esc_url( get_field("meetup_group_link') ); ?>">
<div class="meetup-card">
<div class="meetup-overlay"></div>
<img src="<?php the_post_thumbnail('medium'); ?>">
<div class="meetup-card-text"><h3><?php the_title(); ?></h3>
<div class="meetup-location"><h4><?php the_field('city'); ?><br><?php the_field('country'); ?></h4></div></div>
</div></a>
<?php endwhile;
endif; ?>
</div>
Then call the file in the php file search.php file
example search.php file
<?php get_header(); ?>
<?php
if (is_post_type_archive('meetup_groups') || is_tax('meetup_groups-category') || is_tax('meetup_groups-tags')){
get_template_part('meetup-groups.php');
} else {
// Add Default WordPress Loop
}
?>
<?php get_foooter(); ?>
This code, depends on how you make custom taxonomy
if (is_post_type_archive('meetup_groups') || is_tax('meetup_groups-category') || is_tax('meetup_groups-tags')){