Query to Retrieve Approval details for OTL Timecard Report

SELECT a.time_building_block_id,
       c.time_building_block_id,
       c.time_building_block_id,
       (SELECT f.approver_id
          FROM hxc_tc_ap_links e,
               hxc_app_period_summary f,
               hxc_time_building_blocks g
         WHERE     e.timecard_id = g.time_building_block_id
               AND f.application_period_id = e.application_period_id
               AND g.time_building_block_id = a.time_building_block_id
               AND g.date_to = hr_general.end_of_time)
          Approver,
       (SELECT f.creation_date
          FROM hxc_tc_ap_links e,
               hxc_app_period_summary f,
               hxc_time_building_blocks g
         WHERE     e.timecard_id = g.time_building_block_id
               AND f.application_period_id = e.application_period_id
               AND g.time_building_block_id = a.time_building_block_id
               AND g.date_to = hr_general.end_of_time)
          Approved_Date
  FROM hxc_time_building_blocks a,
       hxc_time_building_blocks b,
       hxc_time_building_blocks c,
       hxc_timecard_summary d
 WHERE     b.parent_building_block_id = a.time_building_block_id
       AND b.parent_building_block_ovn = a.object_version_number
       AND c.parent_building_block_id = b.time_building_block_id
       AND b.parent_building_block_ovn = b.object_version_number
       AND a.scope = 'TIMECARD'
       AND b.scope = 'DAY'
       AND c.scope = 'DETAIL'
       AND c.date_to = hr_general.end_of_time
       AND b.date_to = hr_general.end_of_time
       AND a.date_to = hr_general.end_of_time
       AND a.time_building_block_id = d.timecard_id
       AND d.approval_status = NVL ( :p_approval_status, d.approval_status)