Tableau does not use the 'in' syntax that SQl uses. However, the same outcome can be accomplished. For example, if this is the data:
Employee Date Hours John Smith 5/6/2004 8 Allan Babel 5/6/2004 8 Tina Crown 5/6/2004 8 John Smith 5/7/2004 9 Allan Babel 5/7/2004 8 Tina Crown 5/7/2004 10 John Smith 5/8/2004 8 Allan Babel 5/8/2004 8 Tina Crown 5/8/2004 9
and the SQL statement is the following:
WHERE Date IN ('5/6/2004', '5/7/2004')
The same results would be returned in Tableau with a calculation similar to the following:
if [Date]=#5/6/2004# or [Date]=#5/7/2004# then [Employee] else 'hide' end
Then, the calculation can be placed on the filter shelf and the 'hide' option can be excluded.
Hope this helps!