Oracle 18c

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CREATE TABLE SampleTable (ColA,ColB,ColC,Desired_ColD,Desired_ColE,Desired_ColF
) as
Select 'A1','B1','C1',64,42,86 from dual union all
Select 'A1','B1',Null,28,24,23 from dual union all
Select 'A1','B1','',13,90,36 from dual union all
Select 'A1','B1','',27,27,82 from dual union all
Select 'A1','B2','C1',50,72,98 from dual union all
Select 'A1','B2','C2',54,58,34 from dual union all
Select 'A1','B2','C3',94,57,69 from dual union all
Select 'A1','B3','C1',91,89,77 from dual union all
Select 'A1','B3','C1',89,16,67 from dual union all
Select 'A1','','C1',50,72,40 from dual union all
Select 'A1','B3','',36,29,53 from dual union all
Select 'A1','B3','C2',69,65,85 from dual union all
Select 'A2','B1','C1',66,87,98 from dual union all
Select 'A2','B2','C1',35,87,85 from dual union all
Select '','B2','C2',56,76,52 from dual union all
Select '','B2','C2',33,79,18 from dual union all
Select 'A2','B2','C2',12,31,42 from dual union all
Select 'A2','B2','C2',11,79,83 from dual union all
Select 'A2','','C3',22,27,12 from dual union all
Select 'A2','B2','C3',38,58,48 from dual union all
Select 'A2','','C3',14,78,50 from dual union all
Select 'A2','B2','',83,33,12 from dual union all
Select 'A2','B3','C2',15,91,15 from dual union all
Select '','B3','C2',10,80,34 from dual union all
Select 'A2','B3','C2',97,76,48 from dual union all
Select 'A3','B1','C1',44,70,53 from dual union all
Select 'A3','B1','C1',38,13,11 from dual union all
Select 'A3','B1','C3',39,47,16 from dual union all
Select 'A3','B2','C1',90,72,13 from dual union all
Select 'A3','B2','C2',59,46,11 from dual
;
30 rows affected

--The Impaler's answer: exists + decode
with Desired_Column_Combination as (
  Select 'A1' ColA,'B2' ColB,'C2' ColC from dual union all 
  Select 'A1' ColA,'B1' ColB,'' ColC from dual union all --Should've 3 records
  Select 'A2' ColA,'' ColB,'C3' ColC from dual union all --Should've 2 records
  Select 'A3' ColA,'B1' ColB,'C1' ColC from dual
)
select * 
from SampleTable S
where exists (
  select 1 from Desired_Column_Combination d
  where decode(s.ColA, d.ColA, 1, 0) = 1
    and decode(s.ColB, d.ColB, 1, 0) = 1
    and decode(s.ColC, d.ColC, 1, 0) = 1
);


COLA
COLB
COLC
DESIRED_COLD
DESIRED_COLE
DESIRED_COLF


A1
B1
null
28
24
23

A1
B1
null
13
90
36

A1
B1
null
27
27
82

A1
B2
C2
54
58
34

A2
null
C3
22
27
12

A2
null
C3
14
78
50

A3
B1
C1
44
70
53

A3
B1
C1
38
13
11


--Google: exists + Intersect
with Desired_Column_Combination as (
  Select 'A1' ColA,'B2' ColB,'C2' ColC from dual union all 
  Select 'A1' ColA,'B1' ColB,'' ColC from dual union all --Should've 3 records
  Select 'A2' ColA,'' ColB,'C3' ColC from dual union all --Should've 2 records
  Select 'A3' ColA,'B1' ColB,'C1' ColC from dual
)
select * 
from SampleTable S
where exists (
  select ColA,ColB,ColC from Desired_Column_Combination
  Intersect
  select ColA,ColB,ColC from dual
);


COLA
COLB
COLC
DESIRED_COLD
DESIRED_COLE
DESIRED_COLF


A1
B1
null
28
24
23

A1
B1
null
13
90
36

A1
B1
null
27
27
82

A1
B2
C2
54
58
34

A2
null
C3
22
27
12

A2
null
C3
14
78
50

A3
B1
C1
44
70
53

A3
B1
C1
38
13
11


--My original syntax: Condition is carefully chosen 
--so that no null value is involved and will give correct result
with Desired_Column_Combination as (
  Select 'A1' ColA,'B2' ColB,'C2' ColC from dual union all 
  Select 'A1' ColA,'B1' ColB,'C3' ColC from dual union all --Should've 3 records
  Select 'A2' ColA,'B2' ColB,'C3' ColC from dual union all --Should've 2 records
  Select 'A3' ColA,'B1' ColB,'C1' ColC from dual
)
select * 
from SampleTable S
where (ColA,ColB,ColC) in (
  select ColA,ColB,ColC from Desired_Column_Combination
);


COLA
COLB
COLC
DESIRED_COLD
DESIRED_COLE
DESIRED_COLF


A1
B2
C2
54
58
34

A2
B2
C3
38
58
48

A3
B1
C1
44
70
53

A3
B1
C1
38
13
11
COLA	COLB	COLC	DESIRED_COLD	DESIRED_COLE	DESIRED_COLF
A1	B1	null	28	24	23
A1	B1	null	13	90	36
A1	B1	null	27	27	82
A1	B2	C2	54	58	34
A2	null	C3	22	27	12
A2	null	C3	14	78	50
A3	B1	C1	44	70	53
A3	B1	C1	38	13	11