WordPress at a glance
filter is not described

user_search_columns filter-hook . WP 3.6.0

Filters the columns to search in a WP_User_Query search.

The default columns depend on the search term, and include 'user_email', 'user_login', 'ID', 'user_url', 'display_name', and 'user_nicename'.

Usage

add_filter( 'user_search_columns', 'filter_function_name_7631', 10, 3 );
function filter_function_name_7631( $search_columns, $search, $this ){
	// filter...

	return $search_columns;
}
$search_columns(array)
Array of column names to be searched.
$search(string)
Text being searched.
$this(WP_User_Query)
The current WP_User_Query instance.

Where the hook is called

WP_User_Query::prepare_query()
user_search_columns
wp-includes/class-wp-user-query.php 544
$search_columns = apply_filters( 'user_search_columns', $search_columns, $search, $this );

Where the hook is used (in WP core)

Does not used.