Creates a query selection for use inside a named list passed to
pxweb_query or pxweb_get. This is useful when a
PXWEB table requires an explicit API filter such as an aggregation or value
set filter.
Usage
pxweb_selection(filter = "item", values)
Value
A pxweb_query_selection_filter object.
Arguments
filter
a PXWEB selection filter, for example "item",
"all", "agg:_Regions 2026.agg", or
"vs:Some valueset".