How can one filter MULTIPLE processes in Activity Monitor? How can I look at several processes at once, instead of just one?

For example… typing in bash, shows bash processes.. how to I show both bash and say httpd?

First thoughts.. bash|httpd, no.  Or bash httpd, no.  Long story short, nothing i tried worked.  Is it possible?
This doesn't seem to be possible with Activity Monitor. Unfortunately top doesn't accept several pids to monitor either, so you have to revert to a half-manual (and rather unelegant) solution using Terminal:

while :; do
    clear
    top -l 1 -pid PID-TO-MONITOR | tail -1
    top -l 1 -pid ANOTHER-PID-TO-MONITOR | tail -1
    sleep 5
done


Given some basic bash skills you can wrap this into a shell script if needed often.

Or open several terminal windows and run top on specific processes in each of them. Might be kind of heavy on your CPU though...