in operator functionality can be used in a metrics query selector as shorthand for multiple OR conditions.
<selectors> <field>=(<value>[, <value>, …])
<selectors>is one or more metadata key-value pairs or keywords that scope your query.
<field>is the field (dimension) you want to match.
<value>is the value of dimension that you want to limit your query to.
This example will match time series in which the value of the
dimX field is one of the strings in the array enclosed in parentheses.
metric=CPU_Total dimX=(123, 345, 567)