If they aren't listed in either of the areas shown below, then unfortunately we don't support those specific cloud assets currently.
VMs (with external IPs)
To find VMs with external IPs, first off head to the hamburger menu on the top left:
You'll then want to go to Compute Engine > VM instances:
This dashboard lists all instances, but in order for them to show up in Intruder, they need to have an External IP:
Cloud DNS
Depending on your account usage this may not have be visible if you don't have Cloud DNS enabled (you would have done so through the Marketplace).
As this is a section that needs to be enabled it might not have been pinned in the hamburger menu but can be found by going to Products & solutions > All products:
You can then navigate to Networking > Network services:
This in turn opens Network services page > Cloud DNS to see a view of any running zones:
