bbp_is_forum_public( int $forum_id, bool $check_ancestors = true )

function bbp_is_forum_public( $forum_id = 0, $check_ancestors = true ) {

	$forum_id   = bbp_get_forum_id( $forum_id );
	$visibility = bbp_get_forum_visibility( $forum_id );

	// If post status is public, return true
	$retval = ( bbp_get_public_status_id() === $visibility );

	// Check ancestors and inherit their privacy setting for display
	if ( !empty( $check_ancestors ) ) {
		$ancestors = bbp_get_forum_ancestors( $forum_id );

		foreach ( (array) $ancestors as $ancestor ) {
			if ( bbp_is_forum( $ancestor ) && bbp_is_forum_public( $ancestor, false ) ) {
				$retval = true;
			}
		}
	}

	return (bool) apply_filters( 'bbp_is_forum_public', (bool) $retval, $forum_id, $check_ancestors );
}