How to restrict access of books at different users

Hi Guys,

I have a scenario that we have 3 books i.e. 1 corporate and 2 tax books under one ledger and operating unit. but we have two different users  who are assigned to maintain corporate book and tax books separately.

Now both users can see and make updates in all 3 books on different forms like addition, depreciation and mass changes etc.  

We want to restrict it on user level. so only relevant corporate book user could be able to see and update in corporate book and  only relevant Tax books user could be able to see and update in tax books.