The ability to have parameters that are dynamically updated is a highly requested feature, but is not currently available.
In this case, however, why does a quick filter on the RUN_DATE not work? I assume you would want everything up to and including a certain date. That is possible on a date filter (use Range of Dates and then select Ending Date). Maybe I'm missing something in your requirements that would prevent a quick filter from working. If so, please let me know.
So how would I add this quick filter to my dashboard as a drop down and updates all of the other workbooks that are part of my dashboard? Also, when I right click on the Run_Date field and select 'Show Quick Filter', it automatically defaults to just the Year. I need Month/Day/Year.
i also misunderstood my own requirements here. The table has the last day of each month, however, i only need to show the date if it is a Quarter End Date (for example, Mar 31st, Jun 30th, Sep 30th, Dec 31st).
i know that throws a little monkey wrench into this whole thing....
So, it sounds like the first step is to make sure you are filtered to only the end of the quarters. That could probably be accomplished with a calculated field that would look something like:
(Month([Date]) = 3 AND Day([Date]) = 31)
OR (Month([Date]) = 6 AND Day([Date]) = 30)
If you create that calculation, add it to the filter shelf and set the filter condition to only give rows where it is true, you will only be working with end of quarter dates.
As far as filtering a date, it's important to understand discrete vs. continuous dates (you might want to search and do some reading). Tableau will default to a discrete date at the highest level of detail with multiple values (in your case, Year). To override the default behavior, right click the field and change it to Continuous. Then drag the field to the filter shelf and then it will prompt you as to how you want to filter it. You can select a Range of Dates if you want to be able to specify a Start and/or End date.
If you want to attach a packaged workbook or even just some sample data, I'd be happy to take a look to see if there is anything else that might help!