For some time we were able to use the search bar to look for cloud users, until a few weeks ago, when we lost this option (possibly after an update).
After some troubleshooting and getting in contact with support, it appears that this feature was actually a bug (caused by lsagent deployment, where it shows the cloud users under an Onprem tab).
I raised a feature request with reference PI-825. For those that could use this feature, please do the same.
Thanks.