title: PowerShell grouping multiple properties
body: <p>I'm trying to figure out how to achieve the following using PowerShell.</p>
  
  <p>I have a list of servers with the following headers: Server, Site, Domain</p>
  
  <p>I want to create multiple sets of servers grouped according to the site and domain. But I'd like to have only 1 server per site per domain in a set.</p>
  
  <p>Each domain may have multiple sites. So each set would potentially contain a single server from each site for each domain. the next set would be the same and so forth.</p>
  
  <p>The idea is to then do some work against the set of servers. </p>
  
  <p>Example:</p>
  
  <pre><code>Server1.domain1.com,Site1,Domain1 
  Server2.domain1.com,Site1,Domain1
  Server3.domain1.com,Site2,Domain1   
  Server1.domain2.com,Site1,Domain2
  Server2.domain2.com,Site2,Domain2
  Server3.domain2.com,Site3,Domain2
  Server1.domain3.com,Site1,Domain3
  Server2.domain3.com,Site2,Domain3
  Server3.domain3.com,Site3,Domain3
  </code></pre>
  
  <p>The sets would be:</p>
  
  <pre><code>Set1: Server1.domain1.com,Server3.domain1.com,Server1.domain2.com,Server1.domain3.com,Server3.domain2.com
  
  Set2: Server2.domain1.com,Server2.domain2.com,Server2.domain3.com
  
  Set3: Server3.domain3.com
  </code></pre>