Dozer - Excluding nested Objects

According to this example you can do Deep Mapping with Dozer :

http://dozer.sourceforge.net/documentation/deepmapping.html

<mapping>
   <class-a>com.github.dozermapper.core.vo.deep.SrcDeepObj</class-a>
   <class-b>com.github.dozermapper.core.vo.deep.DestDeepObj</class-b>
   <field>
       <a>srcNestedObj.src1</a>
       <b>dest1</b>
   </field>
   <field>
       <a>srcNestedObj.src2</a>
       <b>dest2</b>
   </field>
   <field>
       <a>srcNestedObj.srcNestedObj2.src5</a>
       <b>dest5</b>
   </field>
</mapping>

Similarly I want to exclude few nested objects and fields, and so I tried same way :

<mapping map-id="case1" map-null="false">
   <class-a>com.server.dal.entities.ClassA</class-a>
   <class-b>com.server.dal.dto.ClassB</class-b>

   <field-exclude>
       <a>childObj1.childObj2</a>
       <b>childObj1.childObj2</b>
   </field-exclude>
   <field-exclude>
       <a>childObj1.childObj3.testMap</a>
       <b>childObj1.childObj3.testMap</b>
   </field-exclude>
 </mapping>

But this is not working as expected. Is there any other way how to exclude nested Object's fields?

You can exclude nested objects as follows :

<mapping map-id="caseClassA" map-null="false">
    <class-a>com.server.dal.entities.ClassA</class-a>
    <class-b>com.server.dal.dto.ClassB</class-b>
    <field map-id="excludeSubItem1">
        <a>childObj1</a>
        <b>childObj1</b>
    </field>
</mapping>

<mapping map-id="excludeSubitem1" map-null="false">
    <class-a>com.server.dal.entities.ClassChild1</class-a>
    <class-b>com.server.dal.dto.ClassChild1</class-b>
    <field-exclude>
        <a>childObj2</a>
        <b>childObj2</b>
    </field-exclude>
    <field map-id="excludeSubItem2">
        <a>childObj3</a>
        <b>childObj3</b>
    </field>
</mapping>

<mapping map-id="excludeSubitem2" map-null="false">
    <class-a>com.server.dal.entities.ClassChild3</class-a>
    <class-b>com.server.dal.dto.ClassChild3</class-b>
    <field-exclude>
        <a>testMap</a>
        <b>testMap</b>
    </field-exclude>
</mapping>