I don’t know of any variable that does this automatically. To do something aside from just copy-pasting the result, you can re-run whatever you just did, eg
vim $(!!)
Where !!
is history expansion meaning ‘the previous command’.
If you expect there to be a single filename with spaces or other characters in it that might prevent proper argument parsing, quote the result (vim "$(!!)"
). Leaving it unquoted will allow multiple files to be opened at once as long as they don’t include spaces or other shell parsing tokens.