For all resource lists the filter applies to multiple columns, normally always at least the the state and name.
For node it's state, name, kube version and OS. It's not a namespaced resources so no-one can filter on it.
Label filtering was something that was proposed a while ago, however I can't find the issue. Community raised issues are important to us, so please can you create one at
https://github.com/rancher/dashboard/issues