This article explains how to add a custom where condition to a flow in TIBCO Data Virtualization Web UI.

1. Open TDV Web UI and create a flow
2. Filter operations can be connected to another operation by dragging the filter operation towards any other operation.
3. Drag the Filter operation from the Operations palette and drop it in the canvas. 
4. Once the Filter operation is added to the data flow diagram, the Filter Configuration pane is displayed
5. For adding the filtering 'where' expression, edit the filtering field 'Filter data where'. 
6. Click on the “Write an Expression” option in the field-specific drop-down list, to write custom expressions. The Expression editor window is displayed.
Example: shipname = 'Able computing'

Screenshot displaying 'Expression editor window': 



Screenshot displaying the custom "where" condition: