You should see this as different chart colors on the Appliance Status-> Uplink page. UNLESS you have two WAN ports, then you lose the real time view of upload/download broken out separately, sadly.
You can also click on an individual client and see the upload / download separately on the client detail page.
Overall, I think better real time visibility (something like iftop on linux) is one of the huge missing pieces on Meraki MX. I've been asking for it for years.
Yes, you have good visibility when looking over a larger time span, but what if you want to see RIGHT NOW.