You cannot use an calculated attribute as a search field in you data view, as the value of the attribute is calculated every time the object is retrieved or loaded into memory. In other words: It has no set value in the database, so a database retrieve would be impossible.
If you can elaborate on what you want to achieve we can maybe come up with some alternatives (Maybe without the calculated attribute involved)?
If you still want to use the calculated attribute you could, for instance, try to make a custom search function:
A ‘string’ text box in which you can type your search parameter, then retrieve the objects on which the calculated attribute resides and then filter this list based on your search parameter. Performance wise, this wouldn't be a great functionality though because, besides loading a (possibly) large amount of unnecessary objects into memory, the calculated attribute microflow is executed once for every object you retrieve. This can have a considerable impact on performance.
Could you explain more or maby show some pictures so it will be more clear? As I'm not sure what you want to do.