How to hide document types from one name space to another while creating documents

we have requirement to hide document types from one name space to another while creating documents.

Ex: I have namespaces A & B, under A i have created document types, under B also i have created document types.

while creating new document under A namespace from hippo UI, i am able to see all document types from A & B. i would like to see only document types related to A not from B.

how to restrict this, kindly help us.

i tried below one didn’t help…

thanks in advance
Ganesh