//Replace the following
/*
cptslug - replace with custom post type slug

parent - replace with parent cpt slug

child - replace with child cpt slug

Column Name - replace with the desired column name.
*/
//Add custom column
add_filter('manage_edit-cptslug_columns', 'my_columns_head');
function my_columns_head($defaults) {
$defaults['Parent'] = 'Column Name';//edit
return $defaults;
}
 
//Add rows data
add_action( 'manage_cptslug_posts_custom_column' , 'my_custom_column', 10, 2 );
function my_custom_column($column, $post_id ){
switch ( $column ) {
case 'Parent':
$parent_id = toolset_get_related_post( $post_id, array( 'parent', 'child' ) );//edit
if($parent_id){
echo get_the_title( $parent_id );
} else {
echo 'No Parent Found';
}
break;
}
}