A permitted receiver is usually a person who works for or assists the Receiving Party somehow. For example, the Receiving Party's lawyers or accountants.
If you are acting for the Disclosing Party, You want to impose various obligations on the Receiving Party regarding permitted receivers. For example, the Receiving Party must require the permitted assigns to sign confidentiality undertakings that are to the satisfaction of the Disclosing Party if the Receiving Party wants to make available the Confidential Information to a permitted receiver.