I often use opengrok.libreoffice.org. Exists something similar for collaboraoffice?
At the moment we don’t have something like that. Once you have a clone of that repo, you can search locally or run ‘git blame’ locally.
The plan is to have Making sure you're not a bot! – but sysadmin needs a bit of time to figure out how to provide that without web crawlers bringing the entire gerrit instance down.