Searching the scrollback buffer

If you are using Terminator then Ctrl-Shift-F allows you to search in the scrollback buffer without needing to run screen or tmux

I don't know about Terminator but an option is to use GNU screen (inside any terminal) which comes with its own scroll buffer which can be searched in copy mode with ?, / like in vi. It doesn't support case insensitive, regex or whole word search though you can add that as an extension by writing a script that dumps the scroll buffer into a file and do whatever you like with it (including telling screen to scroll up to a given location and position the cursor in copy mode).