SQL Server 2019

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select @@version;


(No column name)


Microsoft SQL Server 2019 (RTM-CU6) (KB4563110) - 15.0.4053.23 (X64) 
	Jul 25 2020 11:26:55 
	Copyright (C) 2019 Microsoft Corporation
	Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)



create table t(x varchar(50), y varchar(50))
insert into t
select '1,11,32' ,'A' union all
select '11,12,28','B' union all
select '1'       ,'C' union all
select '32,12,1' ,'D' 
4 rows affected

select distinct x
  from t
 cross apply string_split(t.x,',')
where value=1 


x


1

1,11,32

32,12,1