Inside this thread "Is there a comments thread search function" I see the following dropdown:
I'm using the Chrome Browser currently but it's working with IExplorer and others as well.
Maybe you need to enable this in your settings somehwere. I don't remember activating it manually though.
But you are right, it is missing inside the comments :-(
@Dolby
Any chance to add this "Thread search" to the comments section as well?