I'm a power user of Vimium, but I haven't figured out how to achieve this:
When I'm browsing, say, Reddit, using "j" and "k" keys to scroll. In the middle of the browsing, there would be some comment that's the root of a large tree (sub-comments). I'd like to collapse the entire tree so I don't have to scroll down many pages to skip over the tree.
I went over the Vimium doc and haven't been able to find this shortcut to select the entire frame / div of a single comment, although I did accidentally pressed on a key that did just that when I was browsing Quora when I moved my keyboard, but I then pressed on every key on the keyboard and wasn't able to reproduce it.
I know Reddit has its own shortcuts, so, say, if I disable "j" and "k" in Vimium for reddit.com, I can use those keys to iterate through comments, but it still doesn't do what I want because it's limited in these ways:
You have to start from the very top. So if you are browsing in the middle and see a big tree and want to collapse it, you have to move the selection from the top one bye one;
I don't want to have to iterate through all comments when I browser in order to select the one I want to collapse, I just want to select the one in my viewport;