Navigation from RAD application to standard component BP_HEAD

I created custom UI component based on RAD (Rapid Application Framework), and i wanted to navigate from it to standard component BP_HEAD (BP partner overview page). I tried to use dynamic navigation. In line when i'am trying to get root entity, program generates error with message that 'BuilHeader' is an object that is  not accessible. What I'am doing wrong? Do my approach to the problem is correct? Following code was included to event method triggered by click on hyperlink in result list:

DATA: lr_nav_descr     TYPE REF TO if_bol_bo_property_access,

        lr_core          TYPE REF TO cl_crm_bol_core,

        lr_nav_serv      TYPE REF TO if_crm_ui_navigation_service,

        lr_header        TYPE REF TO cl_crm_bol_entity,

        lr_entity        TYPE REF TO cl_crm_bol_entity,"cl_bsp_wd_value_node,

        lv_partner_guid  TYPE crmt_genil_object_guid,

        lr_col           TYPE REF TO cl_crm_bol_bo_col.

  DATA: lv_partner       TYPE bu_partner,

        lv_index         TYPE sytabix,

        lv_guid          TYPE crmt_genil_object_guid.

* Let's get current row info

  CALL METHOD cl_thtmlb_util=>get_event_info

    EXPORTING

      iv_event = htmlb_event_ex

    IMPORTING

      ev_index = lv_index.

* Get entity for the current row

  CLEAR: lv_guid.

  lr_entity ?= typed_context->searchresultnode->collection_wrapper->find( iv_index = lv_index ).

  IF lr_entity IS BOUND.

    lv_partner = lr_entity->get_property_as_string( iv_attr_name = 'ZZPARTNER' ).

  ENDIF.

  CALL FUNCTION 'CONVERSION_EXIT_ALPHA_INPUT'

    EXPORTING

      input  = lv_partner

    IMPORTING

      output = lv_partner.

  SELECT SINGLE partner_guid FROM but000 INTO lv_partner_guid WHERE partner = lv_partner.

* Get the BOL Core Instance

  lr_core ?= cl_crm_bol_core=>get_instance( ).

* get the BuilHeader object

  lr_header = lr_core->get_root_entity( iv_object_name = 'BuilHeader'

                                        iv_object_guid = lv_partner_guid ).

* add the Builheader to the collection

  CREATE OBJECT lr_col.

  lr_col->if_bol_bo_col~add( iv_entity = lr_header

                             iv_set_focus = abap_true ).

  cl_crm_ui_descriptor_obj_srv=>create_ui_object_based(

           EXPORTING

                     iv_ui_object_type   = 'BP_ACCOUNT'

                     iv_ui_object_action = 'B'

           RECEIVING rr_result           = lr_nav_descr ).

  lr_nav_serv = cl_crm_ui_navigation_service=>get_instance( ).

* check if navigation is possible

  IF lr_nav_serv->is_dynamic_nav_supported( ir_descriptor_object = lr_nav_descr ) = abap_true.

    lr_col->if_bol_bo_col~insert( iv_bo    = lr_nav_descr

                                iv_index = 1 ).

*   start the navigation

    lr_nav_serv->navigate_dynamically( iv_data_collection = lr_col ).

  ENDIF.