Dimensions can be explored in a tree like fasion where the data gets nested in the URL path a full example would be:
http://localhost:8080/collections/fifo/metrics/BmFjdGlvbgVjb3VudA==/namespaces//tags/host/values
collection: "fifo"
metric: ["action", "count"]
namespace: ""
tag: "host"
Please note the due to the fact that metrics in DDB are list not flat values the metric key must be base64 encoded. It will be retured in an object (key: metric path) when the collecton is queried. The base64 encoded value does not need to be computed on the frontend.