Show called # when inbound call comes in

It will be useful to show the called # when an inbound call comes in. I have 2 businesses and 1 business uses my company main and RC support and I have managed to amend settings to allow the called # to show when a call comes in. However we have been unable to show the called # for the 2nd telephone # I have. This is important since I need to know which business the inbound call relates to so that I know how to answer the phone.