create table A(
  entity VARCHAR2(25)
);
insert into A values('555');
commit;

WITH data AS (SELECT * FROM XMLTABLE('/m/r'
            PASSING XMLTYPE('<m>
    <r><e>555</e></r>
    <r><e>1</e></r>
    <r><e>2</e></r>
    <r><e>3</e></r>
</m>') COLUMNS entity VARCHAR2(25) PATH 'e')
)              
SELECT entity FROM data d 
WHERE exists(
     SELECT 1 FROM A a where d.entity = a.entity
);

create index a_idx on A(entity);

WITH data AS (SELECT * FROM XMLTABLE('/m/r'
            PASSING XMLTYPE('<m>
    <r><e>555</e></r>
    <r><e>1</e></r>
    <r><e>2</e></r>
    <r><e>3</e></r>
</m>') COLUMNS entity VARCHAR2(25) PATH 'e')
)              
SELECT distinct d.entity FROM data d, A a where d.entity = a.entity  

WITH data AS (SELECT column_value as entity from TABLE(SYS.DBMS_DEBUG_VC2COLL('555', '1', '2', '3')))  

 WITH data AS (SELECT /*+ materialize */* FROM XMLTABLE('/m/r'