Hi,
Version 2.20 (in beta but close to final) has the spyoptions feature that you can use to limit chanspy to certain groups. That is a chanspy feature, fop2 just lets you pass the appropiate options to it.
You can create groups or panel contexts since previous FOP2 versions too. You can create a group "sales", add only the extension-agents from the sales department. And then assign that group to the sales manager user. The other buttons will not be displayed at all.