User has a pc plugged into a Meraki switch which is connected to a Meraki MX. User's company has a Geo-IP L7 Firewall rule on the MX blocking any traffic that is not from the US. User needs a specific group of websites from other countries but still wants all other traffic from those countries blocked. What would be a way for the user to create an allow for those specific sites without unblocking countries or whitelisting pcs?
Without ever used it myself I would recommend a Group Policy for this User.
Networkwide - Group-Policy
There you are able to configure everything for this single User.
Do you have Active Directory? You can integrate it with your MX and associate MX group policies to specific users in AD: https://documentation.meraki.com/MX/Content_Filtering_and_Threat_Protection/Configuring_Active_Direc...
You can't block a country and then allow one site through from that block.
However @Nash proposal of using a group policy applied to that specific user to remove the geo block is the best idea.