Just create a calculation that ANDs both of these conditions and use it in a filter.
As Dmitry suggests, you would write something like this...
IF [quarter] = 'Q3' AND [category] = 'deal closed' THEN TRUE ELSE FALSE END
The True branch, would be the values you wish to return, sales, profit etc.
The False branch like null
IF [quarter] = 'Q3' AND [category] = 'deal closed' THEN [values] ELSE NULL END
You'll need to swap the items above in [ ] to your real values.