As per the following resource https://docs.cribl.io/stream/environment-variables/#cribl_tmp_dir Cribl temporary files are stored in /tmp, these files are then removed by systemd-tmpfiles-clean.service. In order to have the files stored in an alternative location other than /tmp the following method can be used.

1) Stop Cribl:
cribl@:/opt/cribl/bin$ systemctl stop cribl

2) Edit the Cribl service:
cribl@:/opt/cribl/bin$ vi /etc/systemd/system/cribl.service

3) Add the following entry to the cribl.service file:
Environment=CRIBL_TMP_DIR=<directory name>

4) Create the new directory and ensure the owner and group is cribl:
cribl@:/opt/cribl/bin$ mkdir <directory name>
cribl@:/opt/cribl/bin$ chown -R cribl:cribl <directory name>

5) Reload systemd:
cribl@:/opt/cribl/bin$ systemctl daemon-reload

6) Start Cribl:
cribl@:/opt/cribl/bin$ systemctl start cribl

7) Check the update has taken effect:
cribl@:/opt/cribl/bin$ ls -l <directory name>
* the sub directory cribl_stream should be present under <directory name> *

Thanks @Brian Yearwood ! Awesome!