Add a watcher to a request

Add a watcher to a request

Hi,

We would like to add watchers to request. 
These watchers would need to have single request permission to read the whole request. 

For now we only have the option between 4 'Requester allowed to view' roles: 
  1. Show only their own requests
  2. Show all their Department requests
  3. Show all their Site requests
  4. Show all requests
The reason why we want this: We receive a request from requester A, we think this request would also affect requester B, we do want to include him/her in a request from requester A.
Now we add requester B in the reply mail (in the CC field), however, they cannot see the original request and it's not always clear what the original request was and other replies/notes are not visible. 

We don't want requester B to see all the requests (or even from his/her site or department),so we don't want to give him/her permissions to see more requests.

Kind regards,