Oracle 21c

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ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
CREATE TABLE table_name (value) AS
SELECT 'A.H.4.1.2.0000.pas A.H.4.1.2.0000.poc A.H.410000.poc A.H.420000.poc A.H.4.1.2.0000.Total A.H.4' FROM DUAL
1 rows affected

SELECT value,
       TRIM(
         REPLACE(
           REGEXP_REPLACE(
             ' ' || REPLACE(value, ' ', '  ') || ' ',
             '(\s\S*\.p(oc|as)\s)|\s\S+\s',
             '\1'
           ),
           '  ',
           ' '
         )
       ) AS updated_value
FROM   table_name


VALUE
UPDATED_VALUE


A.H.4.1.2.0000.pas A.H.4.1.2.0000.poc A.H.410000.poc A.H.420000.poc A.H.4.1.2.0000.Total A.H.4
A.H.4.1.2.0000.pas A.H.4.1.2.0000.poc A.H.410000.poc A.H.420000.poc


SELECT value,
       TRIM(
         REPLACE(
           REGEXP_REPLACE(
             ' ' || REPLACE(value, ' ', '  ') || ' ',
             '\s\S*\.p(oc|as)\s'
           ),
           '  ',
           ' '
         )
       ) AS updated_value
FROM   table_name


VALUE
UPDATED_VALUE


A.H.4.1.2.0000.pas A.H.4.1.2.0000.poc A.H.410000.poc A.H.420000.poc A.H.4.1.2.0000.Total A.H.4
A.H.4.1.2.0000.Total A.H.4