SLA working how to define customer category

Hi,

I am working on SLA, Under SLA --> Applicable when  trying to set customer category equal to Platimum.  But when i click browse button i am just getting preferred and standard customer. 

So how do i define my customer type like  Silver / Platinum / Gold.

working on following link.

http://blogs.msdn.com/b/mvpawardprogram/archive/2015/01/19/insider-s-guide-to-managing-services-level-agreements-with-dynamics-crm-2015.aspx

Thanks