remove related entity records

Hi All,

I have one mother  entity    'BTHeaderPartnerSet',  which contains the relation ship enties those are having the data .

One of the relation ship entity is '  BTPartnerOpportunity' , which contains the all partners data those are existing in opportunity .  According to my requirement I need to remove or delete some records from above entity '   'BTPartnerOpportunity'  by chekcing the partner function . Please help me in this .

    IF lr_entity IS BOUND.
    lr_partnerset = lr_entity->get_related_entity( iv_relation_name = 'BTHeaderPartnerSet' ).
    IF lr_partnerset IS BOUND.
      lr_partneropp = lr_partnerset->get_related_entities( iv_relation_name = 'BTPartnerOpportunity' ).
      IF lr_partneropp IS BOUND.
        lr_iterator = lr_partneropp->get_iterator( ).
        lr_iterator->filter_by_property( iv_attr_name = 'PARTNER_FCT'
                                         iv_value     = 'Z000003' ).

even though I have used filter by property it is not working .

Regards,

Ram