It is often the case that developers will want to distinguish different groups of tests, based not on their class association or suite hierarchy, but instead on what kind of test they are. Unit tests, functional, component, and system tests can and likely will be scattered throughout the suite hiearchy.

There are times when you want to distinguish and run only a certain group of tests. For these situations, the appropriate tool is FlexUnit filtering.

Check out the FlexUnit docs at in for the built in functionality and an example of how to use filters:

Filters Reference:
Sample Custom Filter: