Cannot see Network drives via my router on iMac

I just purchased a new iMac today, set everything up and find that my 2 network drives that are connectd to my BT buiness hub 3 router are not showing in finder and I cannot remember what to do. I have a time capsule as well as a WD Network drive.

They both show on my old iMac (Early 2011) but on my new on they are not in my finder window?

Any help appreciated.