How can one filter MULTIPLE processes in Activity Monitor?

Solution 1:

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...

Solution 2:

Not sure when this feature was added (the original question is 8 years old at the time of this writing) BUT, this is possible now. Just hold ⇧SHIFT or ⌘COMMAND to select multiple processes in the Activity Monitor window, and then go to the View menu and choose Selected Processes:

in Big Sur 11.0.1 it looks like this

example, filtering only airportd, authd and bird