You would be better off doing this in your dataset query. Assuming you are using SQL Server. then you can do the following.
You will need a string split function. If using SQL 2016 or later you can use the built-in function string_split(). If you are using an older version then there are plenty of examples of functions you can use. I can supply one if you can't find one.
If all your data comes in a single row then you can do something like this, replacing the @string with your table column.
declare @string varchar(max) = 'Data1, Data2, Data3'
select result = ltrim(rtrim(value)) from string_split(@string,',')
This will give the following results

If you have data on several rows then you can do a similar thing but use CROSS APPLY to repeat the function for each row.
Here's an example
declare @t table (string varchar(max))
insert into @t VALUES
('Data1, Data2, Data3'),
('DataA, DataB, DataC')
select result = ltrim(rtrim(x.value)) from @t
cross apply string_split(string,',') as x
which gives the following result
