How to limit access to an app?

[fishscene]

I have 2 "apps" (Printer config pages).

I want "user A" to have access to "Printer A"
I want "user B" to have access to "Printer A" and "Printer B"

Is there any way I can do this?

The following makes sense to me, but this does not appear to be how DashMachine works:

[UserA]
groups = PrinterA_group

[UserB]
groups = PrinterB_group,PrinterA_group

[PrinterA_group]
type = group

[PrinterB_group]
type = group

[Printer A]
groups = PrinterA_group

[Printer B]
groups = PrinterB_group

This way, UserA sees "Printer A", but not "Printer B".
UserB sees both printers.

Right now, I can't find anyone, anywhere who wants to do this or has an example.
Feel free to build a basic config from scratch. I can translate things from there.