Support negative count on urlparent

For example, Let's assume that URL is https://example.com/aaa/bbb/ccc/ddd/eee.
Pressing gu goes to https://example.com/aaa/bbb/ccc/ddd and 2gu goes to https://example.com/aaa/bbb/ccc

Sometimes, URL is too long and want to leave top N most part of the url.
I suggest:
Pressing -1gu goes to https://example.com/aaa and -2gu goes to https://example.com/aaa/bbb

It would be useful on some websites like reddit