When the person who built a dashboard adds Permanent Filters, they apply every time anyone opens it. The dashboard's header shows Permanent filters active so you know the numbers are already filtered.

[Image: A dashboard header with the "Permanent filters active" indicator]

You can add your own filters on top, but you can't remove the permanent ones. If a dashboard is filtered in a way that doesn't fit what you need, ask its owner or your admin for a different dashboard, or for a change to this one.