//Models
public class People
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public List<Relation> Relations { get; set; }
}

public class Relation
{
public int Id { get; set; }
public int ParentPeopleID { get; set; }
public int ChildPeopleID { get; set; }
public People People { get; set; }
}

//Mapping
HasRequired(p => p.People).WithMany(p => p.Relations).HasForeignKey(p => p.ParentPeopleID);

//Calling
var Peoplelist = MyDbContext.People.Include(p=>p.Relations.Select(r=>r.People)).Where(p=>p.Id==1).ToList();
//or
var Peoplelist = MyDbContext.People.Include(p=>p.Relations.Select(r=>r.People)).ToList();