Customize the Jetpack Related Posts Widget

exclude-category.php

<?php
//* Do NOT include the opening php tag shown above. Copy the code shown below into functions.php of your child theme.
//* This code courtesy of Jetpack 

function jetpackme_filter_exclude_category( $filters ) {
    $filters[] = array( 'not' =>
      array( 'term' => array( 'category.slug' => 'category' ) )
    ); // Replace 'category' with the slug of the category to exclude
    return $filters;
}
add_filter( 'jetpack_relatedposts_filter_filters', 'jetpackme_filter_exclude_category' );

hide-related-posts.php

<?php
//* Do NOT include the opening php tag shown above. Copy the code shown below into functions.php of your child theme.

//Exclude Specific Post from Related Posts
function exclude_posts_related( $exclude_post_ids, $post_id ) {
    //$post_id is the post we are currently trying to get related posts for
      $exclude_post_ids[] = 1145; // Replace with post_id of the post to exclude; duplicate this line for multiple
      return $exclude_post_ids;
}
add_filter( 'jetpack_relatedposts_filter_exclude_post_ids', 'exclude_posts_related', 20, 2 );

related-posts-for-pages.php

<?php
//* Do NOT include the opening php tag shown above. Copy the code shown below into functions.php of your child theme. 
//* This code courtesy of Jetpack 

function jetpackme_allow_pages_for_relatedposts( $enabled ) {
    if ( is_page() ) {
        $enabled = true;
    }
    return $enabled;
}        
add_filter( 'jetpack_relatedposts_filter_enabled_for_request', 'jetpackme_allow_pages_for_relatedposts' );

specific-post-first-specific-post.php

<?php
//* Do NOT include the opening php tag shown above. Copy the code shown below into functions.php of your child theme.
//* This code courtesy of Jetpack 

function jetpackme_append_related_post( $hits, $post_id ) {
    // $post_id is the post we are currently getting related posts for
        if ( 2194 == $post_id ) {
            // Add specific post (post_id) to the front of the hits array
        array_unshift( $hits, array( 'id' => 1036 ) );
            // Remove the last element of the array
            array_pop( $hits );
        }
 
    return $hits;
}
add_filter( 'jetpack_relatedposts_filter_hits', 'jetpackme_append_related_post', 20, 2 );