@ImAMacGuy If you're trying to do this purely via Smart Group criteria then the Boot Drive Percentage Full is probably your best bet. If you're open to using the Jamf Pro API then you can look at the storage data for a device to determine what percentage of the Data partition is in use (to be clear the API returns all of the partitions on the disk, I just edited it down to the Data one which is where user files live):
"storage": {
"bootDriveAvailableSpaceMegabytes": nnnnnnn,
"disks": [
{
"id": "nnnnnnnnn",
"device": "disk0",
"model": "APPLE SSD AP1024Z",
"revision": "2077.100",
"serialNumber": "nnnnnnnnn",
"sizeMegabytes": nnnnnnnnn,
"smartStatus": "Verified",
"type": "NO",
"partitions": [
{
"name": "Data",
"sizeMegabytes": 994662,
"availableMegabytes": 682966,
"partitionType": "OTHER",
"percentUsed": 30,
"fileVault2State": "ENCRYPTED",
"fileVault2ProgressPercent": 100,
"lvmManaged": false
}
]
}
]
},
you would think it would be easy to get what you see in Finder > Get Info like this via Terminal but its not due to Containers, volumes and security what I've determined is
Finder shows everything, your files, system files, hidden backups (snapshots), and purgeable space.
Terminal tools like df or diskutil only see parts of the disk — mostly your files, not hidden system stuff.
macOS uses APFS volumes and snapshots, which Terminal can’t fully see due to security (SIP) and how disks are structured, which why a script shows less used space than Finder — the “missing” GB is hidden but still there.

you would think it would be easy to get what you see in Finder > Get Info like this via Terminal but its not due to Containers, volumes and security what I've determined is
Finder shows everything, your files, system files, hidden backups (snapshots), and purgeable space.
Terminal tools like df or diskutil only see parts of the disk — mostly your files, not hidden system stuff.
macOS uses APFS volumes and snapshots, which Terminal can’t fully see due to security (SIP) and how disks are structured, which why a script shows less used space than Finder — the “missing” GB is hidden but still there.

The one-off identification is one thing, but I'm trying to see in a more wholistic way the fleet's storage in use vs storage available. I want to be able to see across the fleet, with the ultimate goal of for example, if 80% of the users are using less than 500gb, then we can save some money on hardware by getting 512g drives rather than 1TB+.
I guess thats going to be an API pull into a DB and some data crunching
this is an EA that I use in my company
#!/bin/sh
#https://www.jamf.com/jamf-nation/discussions/12546/boot-volume-free-space-ea
DU=$(df -h /Users | awk 'END{ print $(NF-4) }' | tr -d '%' )
# print the reuslts padding with leading 0
echo "<result>$(printf "%02d\\n" $DU)</result>"
and then I use that EA to create a smart group along with nice GUI to display to the users about their disk space: https://github.com/ScottEKendall/JAMF-Pro-Scripts/tree/main/LowDiskSpace