SQL Server 2017

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with t as (
      select v.*
      from (values ('2:21,5:50,4:55,7:80,9:33', '2:12,5:40,4:35,7:60,9:87', '2:52,5:90,4:75,7:30,9:57', '2:42,5:60,4:95,7:70,9:37')
           ) v(FutureMISBoundaryVersion, CurrentMISBoundaryVersion, FutureHAMBoundaryVersion, CurrentHAMBoundaryVersion )
     ),
     cte as (
      select convert(varchar(max), left(FutureMISBoundaryVersion, charindex(',', FutureMISBoundaryVersion) - 1)) as FutureMISBoundaryVersion,
             convert(varchar(max), left(CurrentMISBoundaryVersion, charindex(',', CurrentMISBoundaryVersion) - 1)) as CurrentMISBoundaryVersion,
             convert(varchar(max), left(FutureHAMBoundaryVersion, charindex(',', FutureHAMBoundaryVersion) - 1)) as FutureHAMBoundaryVersion,
             convert(varchar(max), left(CurrentHAMBoundaryVersion, charindex(',', FutureMISBoundaryVersion) - 1)) as CurrentHAMBoundaryVersion,
             stuff(FutureMISBoundaryVersion, 1, charindex(',', FutureMISBoundaryVersion), '') + ',' as FutureMISBoundaryVersion_rest,
             stuff(CurrentMISBoundaryVersion, 1, charindex(',', CurrentMISBoundaryVersion), '') + ',' as CurrentMISBoundaryVersion_rest,
             stuff(FutureHAMBoundaryVersion, 1, charindex(',', FutureHAMBoundaryVersion), '') + ',' as FutureHAMBoundaryVersion_rest,
             stuff(CurrentHAMBoundaryVersion, 1, charindex(',', CurrentHAMBoundaryVersion), '') + ',' as CurrentHAMBoundaryVersion_rest,
             1 as lev
      from t
      union all
      select convert(varchar(max), left(FutureMISBoundaryVersion_rest, charindex(',', FutureMISBoundaryVersion_rest) - 1)) as FutureMISBoundaryVersion,
             convert(varchar(max), left(CurrentMISBoundaryVersion_rest, charindex(',', CurrentMISBoundaryVersion_rest) - 1)) as CurrentMISBoundaryVersion,
             convert(varchar(max), left(FutureHAMBoundaryVersion_rest, charindex(',', FutureHAMBoundaryVersion_rest) - 1)) as FutureHAMBoundaryVersion,
             convert(varchar(max), left(CurrentHAMBoundaryVersion_rest, charindex(',', CurrentHAMBoundaryVersion_rest) - 1)) as CurrentHAMBoundaryVersion,
             stuff(FutureMISBoundaryVersion_rest, 1, charindex(',', FutureMISBoundaryVersion_rest), '') as FutureMISBoundaryVersion_rest,
             stuff(CurrentMISBoundaryVersion_rest, 1, charindex(',', CurrentMISBoundaryVersion_rest), '') as CurrentMISBoundaryVersion_rest,
             stuff(FutureHAMBoundaryVersion_rest, 1, charindex(',', FutureHAMBoundaryVersion_rest), '') as FutureHAMBoundaryVersion_rest,
             stuff(CurrentHAMBoundaryVersion_rest, 1, charindex(',', CurrentHAMBoundaryVersion_rest), '') as CurrentHAMBoundaryVersion_rest,
             lev + 1
      from cte
      where FutureMISBoundaryVersion_rest like '%,%'
     )
select FutureMISBoundaryVersion, CurrentMISBoundaryVersion, FutureHAMBoundaryVersion, CurrentHAMBoundaryVersion, lev
from cte

FutureMISBoundaryVersion	CurrentMISBoundaryVersion	FutureHAMBoundaryVersion	CurrentHAMBoundaryVersion	lev
2:21	2:12	2:52	2:42	1
5:50	5:40	5:90	5:60	2
4:55	4:35	4:75	4:95	3
7:80	7:60	7:30	7:70	4
9:33	9:87	9:57	9:37	5