In Studio > Feedback, you can set the default visibility for feedback and praise, as well as enable/disable certain visibility options 

Default visibility and visibility options

In the settings tab, you can change the default visibility for feedback (requests) and praise with the dropdown menus at the top of each section. Below that, you can select the different visibility options users can choose from when they're sending out praise or feedback. For example: if you don't want users to send praise that's visible for the entire company, you can disable that option here.

Settings for praise

Settings for Feedback and Feedback Requests.