Unable to do Point in Time Recovery in DB2

I am not a DB2 expert, but I know this about NetBackup:
It will restore whatever is requested. Nothing more, nothing less. 

The NBU utilities certainly have limitations. 
We see this in NBU for DB2 manual:

The NetBackup for DB2 database wizards can create backup and
recovery templates. You can launch the backup wizard and the
recovery wizard from the Backup, Archive, and Restore interface.
The wizards generate platform-independent templates containing
configuration information the software uses during backups and
restores. Before you can create, modify, delete, or rename
templates on the master server, the client must exist in a policy or
in the NetBackup image catalog. Because the wizard-generated
templates do not support all the features native to DB2, you may
want to write a customized backup or restore script. You should
use an operating-system defined scripting language to create the
scripts and use a template as the base for a script. 

And:

Because recovery can be a complex process, it might be necessary to perform
manual steps as part of the operation. For more information, see your DB2
documentation.

So, for point in time recovery, best to use DB2 documentation for RECOVER commands/options.

This looks like a good starting point:

https://www.ibm.com/support/knowledgecenter/en/SSEPEK_10.0.0/ugref/src/tpc/db2z_pointintimerecovery.html