Currently, filters can be either personal or shared. It would be nice to share filters for specific groups only, so that only users which have access to those groups also see the filters.
Workaround
It is possible to prevent the proliferation of filters in the dropdown by naming them consistently (Sales, Support, SysAdmin, Dev) and then using BugMonkey customizations to hide the ones that are not relevant to you or your team. You can make the customization required for groups of users you want to keep from seeing the filter.
http://fogbugz.stackexchange.com/questions/10034/how-do-i-hide-a-filter-from-the-dropdown