new.haml

    %ul#addresses
        -each address in agency.addresses
        %li
          %ul
            -inputName = 'agency[addresses]['+address._id+']'
            %li
              %label{for: inputName + '[name]'} 
              Name
              %input{type: "text", name: inputName + "[name]", value: address.name}
            %li
              %label{for: inputName+'[street1]'} 
                Address 
                %input{type: "text", name: inputName + "[street1]", value: address.street1}
            %li
              %label{for: inputName+'[street2]'} 
                Apt/Suite              
                %input{type: "text", name: inputName + "[street2]", value: address.street2}
            %li
              %label{for: inputName+'[city]'}
                City
                %input{type: "text", name: inputName + "[city]", value: address.city}
            %li
              %label{for: inputName+'[state]'}
                State
                %select{ name : inputName+ "[state]"}
                  %option{value: '', selected: agency.type == ''} 
                  %option{value: 'ca', selected: agency.type == 'ca'} California
                  %option{value: 'sc', selected: agency.type == 'sc'} South Carolina
            %li
              %label{for:inputName+'[zip]'}

output.html

<ul id="addresses">
<li>
<ul>
<li>
<label for="agency[addresses][4e81fffc40b613d509000004][name]"></label>Name
<input type="text" name="agency[addresses][4e81fffc40b613d509000004][name]"/></li>
<li>
<label for="agency[addresses][4e81fffc40b613d509000004][street1]"></label>Address
<input type="text" name="agency[addresses][4e81fffc40b613d509000004][street1]"/></li></ul>
<li>
<label for="agency[addresses][4e81fffc40b613d509000004][street2]"></label>Apt/Suite
<input type="text" name="agency[addresses][4e81fffc40b613d509000004][street2]"/></li></li>
<li>
<label for="agency[addresses][4e81fffc40b613d509000004][city]">City
<input type="text" name="agency[addresses][4e81fffc40b613d509000004][city]"/></label></li>
<li>
<label for="agency[addresses][4e81fffc40b613d509000004][state]">State
<select name="agency[addresses][4e81fffc40b613d509000004][state]">
<option ></option>
<option value="ca">California</option>
<option value="sc">South Carolina</option></select></label></li>
<li>
<label for="agency[addresses][4e81fffc40b613d509000004][zip]">Zip
<input type="text" name="agency[addresses][4e81fffc40b613d509000004][zip]"/></label></li>
</ul>
</select>
</form>