You might consider a subset of data for your initial query.. something such as locations and dates as the only two fields in a separate data source. This would be your selection view. Then on a second view show, add in the list of all dates and locations. This second view will be your "answer" view and only appear when selecting a date from the first view. See the attached example (sort of - since this has all the superstore data copied twice). Hopefully this idea gives you ideas for moving forward.
Sorry - this example is in v10 but it will work with other versions the same way as there is nothing v10 specific. Note that you can install v10 and v9 side by side on your desktop. To set v9 to be the default version when opening Tableau files, just reinstall the latest v9 version.
I hope this helps.
Thanks for your response Patrick.
I downloaded the workbook but it wouldn't open (I checked and I'm on 9.0.4). And I can't install v10 due to my company's restriction on employees installing software themselves!
I think what you are describing is similar to what I am already doing - albeit I don't have a separate data source with just location and date.
But I think my question is more generic anyway. It's more about understanding the order Tableau does operations in. I have seen really helpful order of operation diagrams (Paint By Numbers: Let's put some things into context - a practical introduction to Context Filters in Tableau) that show Data Source Filters are done before Context Filters, which are done before Set Filters etc. But these never seem to mention Action Filters.
I am assuming Action Filters get done at the same time as other Dimension Filters (assuming that my Action filter is on a Dimension anyway). And that if I were to turn *other* filters into Context filters, it would ensure the Context filters got done before the Action filter. But I am only assuming that!
I'm also interested in how Tableau processes multiple Dimension filters. What order does it do them in? Does it do the one at the top of the Filters Shelf first?