We are not able to use the Greater than or Less than operators in LDAP search filter for eTSAPUserGroupValidFrom or eTSAPUserGroupValidTo.
Release : 14.x
Component : IdentityMinder(Identity Manager)
eTSAPUserGroupValidFrom (as well as eTSAPUserGroupValidTo) are both defined as String on in the schema - you can check this by running dumpptt on the SAP parser file
C:\CA\Identity Manager\Provisioning Server\bin>dumpptt.exe -f -t ..\data\sapparse.ptt -of d:\temp\sapptt.txt
ATTRIBUTE (LDAP Name) eTSAPAccount::eTSAPUserGroupValidFrom
User-friendly Name : SAPUserGroupValidFrom
Description: First valid date
EditType: 0 [string]
Case: 0 [insensitive]
DataLocation: 1 [AGENT]
AuthOps: 0x14 (Modify, Owner)
Since it is defined as a string, it does not support greater than / less than comparison attempts.
With this being the designed configuration, it would require an Enhancement Request (Idea) for the change to be considered by Product Management.
In the meantime, to get the required functionality, proceed by mapping these attributes to a custom global user field (and possibly IM too) so the date could be used in the PX, as needed.