I know this feature may come out in Kiln in the future, but would like to try it out.
If you have the tezos node command, you can run a snapshot command on the /var/lib/kiln/data-dir/tezos-node/NetXdQprcVkpaWU directory.
kiln-shell doesn't currently export the tezos-node command, though, so you may have to build tezos-node from source for the time being.
Then you can run the command like so:
tezos-node snapshot export --block BMN9fiLSLu8HGza51qH4C8RoLVS5G9zBZKLehYDZiruNriqTSee mainnet.full --data-dir /var/lib/kiln/data-dir/tezos-node/NetXdQprcVkpaWU
We really should get the tezos-node accessible via the shell until kiln can snapshot for you! :)