Making a filter 'required' on all smart lists

[Anonymous]

We are a non-profit, consisting of 80 'chapters' each having their geographical region of activity. We are having a unique problem where a lead can belong to more than 1 chapter - a classic example is:when a lead stays in New York but donated at a Gala attended in California. In this case, we want the lead accessible to both the California chapter and NY chapter. As a result, to keep the database open, we have not implemented partitions, and the entire US lead database is accessible to all users. 
With this sort of architecture, there's a chance that a user can mail the entire database if he/she forgets to add any essential filter.
As a work around, we have created smart lists for each chapter, which consist of all potential leads the chapter will ever have to email. Continuing the example above, the smart list for california will be the union of All leads living in California AND All Leads which attended a Gala in California. This way, we filter out all other leads which dont satify the criteria and hence limit the max leads that can be emailed.
But if the user does not use this list as a filter, he/she might end up emailing leads for other chapters.

So, is there any way we can make adding this smart list 'required' as a filter for all chapter created lists? 
Is there any other more efficient way to resolve the problem above?

Thanks!                  

[Anonymous]

An alternative for you could be to leverage segments more, as no lead can belong to more than 1 at a time.

That being said, if your org has 80 chapters, I don't believe you're allowed to create that many segments in your Marketo instance (I think it might be capped around 25, but can't remember for sure).

Regardless, as an admin, I'd love the ability to require certain filters in smart lists, in some capacity (i.e. suppress competitors, customers, etc.)