on the netbackuo console, if you expand devices tab, you can click on topology to view your NBU environment.

i really dont think netbackup has a feature like that for now.

I try to help you out. See below

I have highlighted the Clients from left site. You can see all Clients which are Netbackup Clients at the right site. If you want to see Master and Media Server you can see those above the Clients at left site 

Thanks...its frustrating because its obviously possible. I mean if every client failed its backup then the topology would naturally display the full topography. But there appears to be know way to display it beyond that.

 Mark me as Solutions If you are satisfied

but rather wants to see ALL of his clients whether they are active/failed or not i.e. everything! This is all well & good, but if the environment contains 00's or 000's of clients then I hope you've got a big screen!

I have seen what I think pjtee is after once or twice, but it generally only appears to happen (for me) if there's a slight glitch with the Admin Console & they all soon disappear if I refresh the screen.

The topology screen shows olny the active client being backed and the failed ones.
This has been so since I can remember.