[Holub]

Okey.
Insert into the end of auth.php before "?>"

if ($login)
	$smarty->assign("cur_membership", func_query_first_cell("select membershipid from $sql_tbl[customers] where login = '$login'"));

This code allows use customer's membershipid if he logged in.
In /skin1/customer/home.tpl insert

{if $cur_membership eq 2}
{include file="customer/categories3.tpl" }
{/if}

Of course, in condition '$cur_membership eq 2' you should use membership ID (customers who can view menu) instead of "2".
You can find out membershipid via code in /skin1/customer/home.tpl

{$cur_membership}    <---- this tag allows you to find out id.
{if $cur_membership eq 2} <---- insert id instead of 2
{include file="customer/categories3.tpl" }
{/if}