Hi Swagi,
Please use this logic it might be helpful for u.
write in DO_PREPARE_OUTPUT
lr_entity ?= me->typed context->BTORDER->collection wrapper->get_current( ).
lr_entity ?= lr_entity->get_related_entity( iv_relation_name = 'BTOrderHeader' ).
lr_entity ?= lr_entity->get_related_entity( iv_relation_name = 'BTHeaderItemsExt' ).
lr_entity ?= lr_entity->get_related_entity( iv_relation_name = ' BTOrderItemAll' ).
CALL METHOD lr_entity->if_bol_bo_property_access~GET_PROPERTY_AS_value
EXPORTING
iv_attr_name = 'ORDERED_PROD'
RECEIVING
ev_result = lv_value.
lr_current ?= me->typed context->BTQRAct ->collection wrapper->get_current( ).
CALL METHOD lr_current->if_bol_bo_property_access~SET_PROPERTY
EXPORTING
iv_attr_name = 'Zproduct'
RECEIVING
iv_value = lv_value.
Please let me know if it is helpful.
Thanks and Regards,
Santosh.