Provide the ability to restrict the viewing of a custom metric to a group

We had set up two custom events with revenue that we wanted to restrict to a defined set of users. So far as I can tell, we have the ability to restrict report access but not a custom event. We can't really make these revenue numbers openly available so we have disabled ours. Can we have the ability to restrict/hide events as well as reports.

NOTE: Adam Greco has pointed out this is existing funtionaltiy. Admin > User Groups > Custom link in the Commerce section