The configuration language in the widgets of riemann-dash
Pattern matching is done with the "=~" operator, and "%" is the wildcard. "|" can be used to give alternative values. Haven't used pipe yet but I believe that alternative values are grouped inside a a pair of brackets: "(val1|val2). See monitoring-setup/dashboard.json at master · algernon/monitoring-setup
service =~ "process:%:cpu:percent"
"Rows" and "Columns" decides if the data will be presented row-wise or column-wise per host.