title: find list using createcriteria nested object property
body: <p>I have a domain like this</p>
  
  <pre><code> Employee {
     Address address
     String name
     String title
  }
  </code></pre>
  
  <p>and another domain </p>
  
  <pre><code> Address {
    String country
    String locality 
    String city
  }
  </code></pre>
  
  <p>and now i want to find the all the employee with given city something like that i tried </p>
  
  <pre><code>  def employees = Employee.where { 
        address {
         city == params.city
          }
     }
  </code></pre>
  
  <p>but this is not working , how can i achieve this </p>