You can add this code to your bp-custom.php file:
add_filter ('bp_ajax_querystring', 'exclude_user1', 20, 2);
function exclude_user1 ($qs, $object)
{
if ($object != 'members') return $qs;
$args = wp_parse_args ($qs);
if (empty ($args['exclude']))
$args['exclude'] = '1';
else
$args['exclude'] .= ',1';
$qs = build_query ($args);
return $qs;
}
Please let me know if it works for you!