gatekeeper

noun
1
a person whose job is to check and control who is allowed to go through a gate
نگهبان, دروازه‌بان, دربان, نگهبان در
2
a person, system, etc. that decides whether somebody/something will be allowed, or allowed to reach a particular place or person
دروازه‌بان, نگهبان ورودی, مسئول ورود و خروج, تصمیم‌گیرنده درباره دسترسی
His secretary acts as a gatekeeper, reading all mail before it reaches her boss.
Literacy and maths are the gatekeeper skills that give kids access to academic success.