XMLTABLE no oracle - incompatibilidade de tipo dinâmico XQuery:sequência singleton esperada - sequência de vários itens obtida

FROM ( SELECT p_region_id,
            p_revision_id,
            p_bg_revision_id,
            p_facility_id,
            p_scp_classification_id,
            p_provider_group_id
      FROM DUAL) p, 
      (SELECT b.bgid, b.ggid
        FROM XMLTABLE(
                '/ProviderGroupScopeOfPractice' 
                PASSING lv_xmldata
                 COLUMNS records XMLTYPE PATH 'Records') r,
                XMLTABLE ( 'Records/Record'
                                 PASSING r.records
                                 COLUMNS bgid  NUMBER (3) PATH '@bgid',
                                        ggid  NUMBER (5) PATH '@ggid'
                                        )b
      ) bgDetails;