How to make comments private for commentor and post author

I am trying to make comments private. I mean comment must be visible for post author and comment author. I create custom comment section. I have used pre_get_comments but I can not make work. Please help

<?php
// My custom comments output html
function better_comments( $comment, $args, $depth ) {

    // Get correct tag used for the comments
    if ( 'div' === $args['style'] ) {
        $tag       = 'div';
        $add_below = 'comment';
    } else {
        $tag       = 'li';
        $add_below = 'div-comment';
    } ?>

    <<?php echo $tag; ?> <?php comment_class( empty( $args['has_children'] ) ? '' : 'parent' ); ?> id="comment-<?php comment_ID() ?>">

    <?php
    // Switch between different comment types
    switch ( $comment->comment_type ) :
        case 'pingback' :
        case 'trackback' : ?>
        <div class="pingback-entry"><span class="pingback-heading"><?php esc_html_e( 'Pingback:', 'textdomain' ); ?></span> <?php comment_author_link(); ?></div>
    <?php
        break;
        default :

        if ( 'div' != $args['style'] ) { ?>
            <div id="div-comment-<?php comment_ID() ?>" class="comment-body">
        <?php } ?>
            <div class="comment-author vcard">
                <?php
                // Display avatar unless size is set to 0
                if ( $args['avatar_size'] != 0 ) {
                    $avatar_size = ! empty( $args['avatar_size'] ) ? $args['avatar_size'] : 70; // set default avatar size
                        echo get_avatar( $comment, $avatar_size );
                }
                // Display author name
                printf( __( '<cite class="fn">%s</cite> <span class="says">says:</span>', 'textdomain' ), get_comment_author_link() ); ?>
            </div><!-- .comment-author -->
            <div class="comment-details">
                <div class="comment-meta commentmetadata">
                    <a href="<?php echo htmlspecialchars( get_comment_link( $comment->comment_ID ) ); ?>"><?php
                        /* translators: 1: date, 2: time */
                        printf(
                            __( '%1$s at %2$s', 'textdomain' ),
                            get_comment_date(),
                            get_comment_time()
                        ); ?>
                    </a><?php
                    edit_comment_link( __( '(Edit)', 'textdomain' ), '  ', '' ); ?>
                </div><!-- .comment-meta -->
                <div class="comment-text"><?php comment_text(); ?></div><!-- .comment-text -->
                <?php
                // Display comment moderation text
                if ( $comment->comment_approved == '0' ) { ?>
                    <em class="comment-awaiting-moderation"><?php _e( 'Your comment is awaiting moderation.', 'textdomain' ); ?></em><br/><?php
                } ?>
                <div class="reply"><?php
                // Display comment reply link
                comment_reply_link( array_merge( $args, array(
                    'add_below' => $add_below,
                    'depth'     => $depth,
                    'max_depth' => $args['max_depth']
                ) ) ); ?>
                </div>
            </div><!-- .comment-details -->
    <?php
        if ( 'div' != $args['style'] ) { ?>
            </div>
        <?php }
    // IMPORTANT: Note that we do NOT close the opening tag, WordPress does this for us
        break;
    endswitch; // End comment_type check.
}