[REQUIRED] Describe your environment

• Operating System version: JS
• Firebase SDK version: 4.11
• Firebase Product: firestore

[REQUIRED] Describe the problem

if we have some data like;

• collection-department

  • dept1
    • collection-employee
      • emp2
      • emp1
  • dept2
    • collection-employee
      • emp5
      • emp8
  • dept3
    • collection-employee
      • emp6
      • emp10

• another-collection

if we want the employees in dept1
db.collection('/collection-department/dept1/collection-employee').get()

we need to get all employees in all department in one request; something like
db.collection('/collection-department/*/collection-employee').get()

my case is efferent but this sample for explanation.. that we cant USE the sub collection feature if we miss this option.. our scenario have a thousand of document that share the same sub-collection and we need to get the data in single request not doing a thousands one...

Thanks