Please don't confuse MSDP dedupe catalogs with the rest of NBU catalogs.
You will have a single mount point for MSDP. The norm is to have 2 subdirectories here - one for MSDP catalog and another for the backup images. The contents under these folders is not really documented and I never felt the need to mess around here.
This mount point needs to be used for MSDP ONLY. NOTHING ELSE.
The location of NBU config and relational databases can be found in the folders as per the section in NBU Admin Guide 1.
If a separate mount point was created for NBU catalogs and relational database, you will find a symbolic link in /usr for openv with the location of the mount point/folder.
If only images folder was moved to another mount point, you will find a symbolic link in /usr/openv/netbackup/db for images.
The location of relational databases can be found in bp.conf.
If you want to move all of NBU config and relational databases to a new mount point (not MSDP mount point), you will find a process in NetBackup in Highly Available Environments Administrator's Guide
The topic is something like catalog replication in non-clustered environment.