In DVI, a filter drop zone is placed over the active crosstab area. By putting a variable in the filter bar, we can narrow the base for the calculations.
Only one filter can be applied at a time, so one variable or one logical expression can be placed in this zone. The quick options available from the pop-up menu are ‘OR-Join’ AND ‘AND-Join’.
If you need to build a more complicated logical expression, follow these steps:
Drag&drop any variable from a codebook to the Filter area;
Click on any area within the filter drop zone to open the expression builder window;
Build new logical expression using OR / AND / ANY OF / NOT logic, add or remove the variables;
Click 'Save' and close the logical expression builder window.
Click 'Calculate'.
Now, all calculations will be filtered with the logical expression in the filter area.
To return to the previous base clear the filter area by clicking on the 'X' icon in its right corner.