Hiding the external Job Requisition to employee (internal candidate)

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Hello there! I'm writing to understand about the possibility to hide to the employee the job requisitions posted on the external career site.

Our client asks to defaulted the "Internal Job" in Job Attributes filter in order to push the employee to view just the job requisitions posted on INTERNAL CAREER SITE: to you, is it a reachable request?

Thinking about the request on the filter, is it possible to defaulted the "Internal Job" filter but also, at the same time, hiding the filters?

I know the paramount topic is related on referral campaign, however our client doesn't like this and prefer close the visibility of the employee...