Verity folder must exist in PS_HOME on the App servers.
Add the above verity folder path to the %PATH% variable.
Do the following in app server configuration
Search Settings:
assign 2 to deploymentType
Search indexes setting:
FDM_PV_ITEMCATALOG=\\BatchServerDNS\%PS_HOME%\data\search
Now, Build Search collection.
Assign catalog search type as VSE.