Yes. Login to the web vault (= login in your browser to vault.bitwarden.com or vault.bitwarden.eu). You can bulk move items into folders there:
You could also set URIs in the items you no longer need to match detection “never”, so that you don’t get them as autofill suggestions - if you were on the corresponding site. (unfortunately, there currently is a bug with the handling of URIs, so maybe postpone that for now until that bug is fixed).