Tags are a great way to segment your environment. One of the ways you can use tags is to filter your dashboard, to focus on only the items that you need to.
For example, in the Servers dashboard, you can filter on any label or tag,
Using tags to filter monitored machines under the “Servers” tab is very handy, but how are tags attached to custom dashboards usable?
Please disregard my previous comment, I found my answer in another article: copperegg.zendesk.com/.../41706996-How-do-I-setup-a-new-custom-dashboard