gatekeeper
(noun)
 A person or group who controls access to something or somebody.
Examples of gatekeeper in the following topics:
- 
Buying Centers
- Gatekeepers - Gatekeepers are typically secretaries and tech personnel.
 - Buyers who deal directly with a vendor are gatekeepers.
 
 - 
Approach
- Other techniques to get a foot in the door include leveraging common contacts or referrals and simply building a relationship through conversation with the gatekeepers to get information on the best way to approach the purchase decision-maker.
 
 - 
The Marketing Plan
- Gatekeepers - those who review the plan for compliance to industry rules and regulations such as in-house legal departments, corporate counsels, regulatory or licensing specialists.