title: Automapper unflatten with prefix
body: <p>I have some DTOs which are mapped from Domain objects thanks to convention-based automapping, i.e. the Address fields are being flattened to the DTO.</p>
  
  <p>This works fine for Domain -> DTO conversion, but the other way I have to "unflatten" the Address manually. </p>
  
  <p>I wonder if there is a possibility to "prefix" the mapping configuration, so I could do something like</p>
  
  <pre><code>Mapper.CreateMap&lt;PersonDTO, Address&gt;().WithPrefix("Address");
  ...
  Mapper.CreateMap&lt;PersonDTO, Person&gt;()
  .ForMember(d =&gt; d.Address, opt =&gt; opt.MapFrom(src =&gt; Mapper.Map&lt;Address&gt;(src) ))
  </code></pre>
  
  <p>otherwise I have to manually map each Address field, which becomes the problem for more complex objects.</p>
  
  <p>my domain objects and the DTO</p>
  
  <pre><code>class Person
  {
      public string FirstName {get;set;}
      public string LastName {get;set;}
      public Address Address {get;set;}
  }
  
  class Address
  {
      public string Street {get;set;}
      public string PostCode {get;set;}
  }
  </code></pre>
  
  <p>and the following DTO:</p>
  
  <pre><code>class PersonDTO
  {
      public string FirstName {get;set;}
      public string LastName {get;set;}
      public string AddressStreet {get;set;}
      public string AddressPostCode {get;set;}
  }
  </code></pre>
  
  <hr>
  
  <p>edit</p>
  
  <p><strong>I'm aware of global configuration "recognized prefixes". I'd rather like to set obligatory prefix (not "one of the recognized") for the specific Map.</strong></p>