As of 8.0, filters based on table calculations are second-class citizens in the world of filters. They can't be global nor work across N worksheets of a data source, and like other aggregate measures they can't be used in Filter Actions (see http://community.tableausoftware.com/ideas/2399) for that Idea. This limits their utility, and forces us to do things like "pushing down" computations into row-level calculations or SQL so we can use a filter on an aggregate measure or even dimension, or to use parameter-based filters.
I can see two avenues to approaching this. In one case, the fields used for addressing and partitioning of the table calculation would have to be the same across all worksheets. In the other, each instance of the table calculation on each worksheet could have its own addressing and partitioning, and the filter is set up to work across the combined domain of all results. I prefer the latter, as it's more flexible and would ultimately enable table calc filters to be used in Filter Actions across data sources. It also works in a similar way to existing measures, for example in the attached workbook where SUM(Sales) is aggregated for each Country in one worksheet and Item in another, and Sales slider filter is working on the domain for both:
I understand that this is asking Tableau to do an additional amount of computation to load the domain, at the least supporting this for booleans and other fields with a fixed domain (such as a worse/better/best KPI) would be useful.
This also relates to http://community.tableausoftware.com/ideas/1314, in the sense that giving filters more options for their scope is helpful.
[edited 20131027 to add screenshot and workbook]