No matter i figured it.
Code:
{if $customer ne ''}{assign var="_userinfo" value=$customer}{else}{assign var="_userinfo" value=$userinfo}{/if}
{config_load file="$skin_config"}
{foreach from=$_userinfo.additional_fields item=v}
{if $v.section eq 'C' || $v.section eq 'P'}
{$v.value}
{/if}
{/foreach}