The Quote tool captures a quote within a quote in a straightforward way, but here is an example of confusion when Discourse quote tags are combined with CSGnet-style attribution tags.
Here is the context from which Eetu was quoting:
The most consistent solution would be to quote from the archive category/topic and retain the tag and link that Discourse provides leading back to the source of the quote.
The other solution, and the only one available in this instance because there is no Discourse tag linking to the source in the archive, is to keep the CSGnet-style quote attribution tag:
Rick did this just before the quoted passage, and this example also shows how the Quote tool in Discourse handles nested quotes: