public class Person
{
  private int id;
  private String name;
  private String departmentName;
  ...
  //get/set methods

  [b]public Set<Person> getOtherPeopleInTheSameDepartment();[/b]
  //this method should return a set of Person objects that has the same departmentName;
}

Table:  Person
Column:
id - int
name - varchar
department - varchar
...

<hibernate-mapping>
    <class name="Person" table="Person" schema="dbo" catalog="Scrap">
        <id name="id" type="int">
            <column name="ID" />
            <generator class="assigned" />
        </id>
        <property name="department" type="string">
            <column name="department" not-null="true" />
        <set name="otherPeopleInTheSameDepartment" inverse="true" lazy="true">
           <key>
            <column name="id" not-null="true" />
            <column name="department" not-null="true" />
      </key>
           <one-to-many class="Person"/>
           <loader query-ref="Person.otherPeopleInTheSameDepartment"/>
        </set>

        <sql-query name="otherPeopleInTheSameDepartment">
           <load-collection alias="p" role="Person.otherPeopleInTheSameDepartment"/>
           select
              {p.*}
           from
              Person p
           where
              p.ID = :id
              and p.department = :department
        </sql-query>
    </class>
</hibernate-mapping>