From where can one download the BIRT designer tool?
Can SuccessFactors provide the repository link for the same?
SuccessFactors Ad Hoc reporting
The Eclipse BIRT Project is an open source Top Level Project of the Eclipse Foundation.
Hence all versions of the BIRT designer can be downloaded from the Eclipse Foundation's BIRT downloads page:
Please note that as of the 2017 Q1 release (B1702), BIRT 2.6.0 is the supported version for SuccessFactors Ad Hoc reports.
2280300-BIRT Eclipse Version Supported for Ad Hoc Reports
KBA , LOD-SF-ANA-ADH , Adhoc Reports & Report Builder , How To