Grafana Variables - At the "Folder" Level?

I’ve created a couple of dashboards and have placed them within Folders. Is it possible to set up variables at the folder level and have the dashboards inherit those variables?

Example: I’m an IT provider who monitor services for multiple customers. I want to allow my customers to log into grafana and be able to see the data that I see. I dont want to create 100 dashboards - 1 per customer with hard-coded values for my queries.

I know variables are possible WITHIN the dashboard, but I can’t find anything for variables existing outside of the dashboard.

Is this possible?