Actually this is part of the dashboard nodes - and as such is no longer under active development - so unless someone wants to jump in and enhance with a pull request, it is unlikely to happen.
I too have 140 groups ! all groups are made since dashboard widgets keep moving if i change the screen from which i am viewing, (i have one small screen on desk and a large TV screen where i display. there may be a better way, but i have invested so much time in developing this, i am liking it a lot not to change anything. it would really be nice if i could 'search' as you said, currently i quickly type [ followed by first letter of group to go there fast.
just curious, if i understood the statement correctly, do you mean you cannot take screenshot like this ?