What would be the conditional for checking the usergroup membership of a specified user?
<xen:if is="!{xen:helper ismemberof, $visitor, x}"> determines if the browsing user is not a member
I'm looking for something like <xen:if is="!{xen:helper ismemberof, <UserId>, x}">
... where <UserId> = the value I specify, returning true if <UserId> is not a member of usergroup x.