function bp_blogs_format_activity_action_new_blog_comment( $action, $activity ) {
	/**
	 * When the comment is published we are faking an activity object
	 * to which we add 4 properties :
	 * - the post url
	 * - the post title
	 * - the blog url
	 * - the blog name
	 * This is done to build the 'post link' part of the activity
	 * action string.
	 * NB: in this case the activity has not yet been created.
	 */

	$blog_url = false;

	// Try to get the blog url from the activity object
	if ( isset( $activity->blog_url ) ) {
		$blog_url = $activity->blog_url;
	} else {
		$blog_url = bp_blogs_get_blogmeta( $activity->item_id, 'url' );
	}

	$blog_name = false;

	// Try to get the blog name from the activity object
	if ( isset( $activity->blog_name ) ) {
		$blog_name = $activity->blog_name;
	} else {
		$blog_name = bp_blogs_get_blogmeta( $activity->item_id, 'name' );
	}

	if ( empty( $blog_url ) || empty( $blog_name ) ) {
		$blog_url  = get_home_url( $activity->item_id );
		$blog_name = get_blog_option( $activity->item_id, 'blogname' );

		bp_blogs_update_blogmeta( $activity->item_id, 'url', $blog_url );
		bp_blogs_update_blogmeta( $activity->item_id, 'name', $blog_name );
	}

	$post_url = false;

	// Try to get the post url from the activity object
	if ( isset( $activity->post_url ) ) {
		$post_url = $activity->post_url;

	/**
	 * The post_url property is not set, we need to build the url
	 * thanks to the post id which is also saved as the secondary
	 * item id property of the activity object.
	 */
	} elseif ( ! empty( $activity->id ) ) {
		$post_url = bp_activity_get_meta( $activity->id, 'post_url' );
	}

	$post_title = false;

	// Should be the case when the comment has just been published
	if ( isset( $activity->post_title ) ) {
		$post_title = $activity->post_title;

	// If activity already exists try to get the post title from activity meta
	} elseif ( ! empty( $activity->id ) ) {
		$post_title = bp_activity_get_meta( $activity->id, 'post_title' );
	}

	// Should only be empty at the time of post creation.
	if ( empty( $post_url ) || empty( $post_title ) ) {
		switch_to_blog( $activity->item_id );

		$comment = get_comment( $activity->secondary_item_id );

		if ( ! empty( $comment->comment_post_ID ) ) {
			$post_url = add_query_arg( 'p', $comment->comment_post_ID, trailingslashit( $blog_url ) );
			bp_activity_update_meta( $activity->id, 'post_url', $post_url );

			$post = get_post( $comment->comment_post_ID );

			if ( is_a( $post, 'WP_Post' ) ) {
				$post_title = $post->post_title;
				bp_activity_update_meta( $activity->id, 'post_title', $post_title );
			}
		}

		restore_current_blog();
	}

	$post_link = '<a href="' . esc_url( $post_url ) . '">' . esc_html( $post_title ) . '</a>';
	$user_link = bp_core_get_userlink( $activity->user_id );

	if ( is_multisite() ) {
		$action  = sprintf( esc_html__( '%1$s commented on the post, %2$s, on the site %3$s', 'buddypress' ), $user_link, $post_link, '<a href="' . esc_url( $blog_url ) . '">' . esc_html( $blog_name ) . '</a>' );
	} else {
		$action  = sprintf( esc_html__( '%1$s commented on the post, %2$s', 'buddypress' ), $user_link, $post_link );
	}

	// Legacy filter - requires the comment object.
	if ( has_filter( 'bp_blogs_activity_new_comment_action' ) ) {
		switch_to_blog( $activity->item_id );
		$comment = get_comment( $activity->secondary_item_id );
		restore_current_blog();

		if ( ! empty( $comment ) && ! is_wp_error( $comment ) ) {
			$action = apply_filters( 'bp_blogs_activity_new_comment_action', $action, $comment, $post_url . '#' . $activity->secondary_item_id );
		}
	}

	/**
	 * Filters the new blog comment action for the new blog.
	 *
	 * @since 2.0.0
	 *
	 * @param string $action   Constructed activity action.
	 * @param object $activity Activity data object.
	 */
	return apply_filters( 'bp_blogs_format_activity_action_new_blog_comment', $action, $activity );
}