Easiest way to Filter Eclipse Console Output text
Nothing specific to FlexBuilder. If you need such a functionality, you'd need to write an Eclipse plug-in.
Take a look at grep-console one to start off.
there is also Easy Console Grepper which opens up own console, easier at first then grep-console I think. Just define what You searching and it will show after console execution lines with searched expression.
Also GrepClipse may help. Also available on the Eclipse Martket.