WordPress at a glance
filter is not described

get_role_list filter-hook . WP 4.4.0

Filters the returned array of roles for a user.

Usage

add_filter( 'get_role_list', 'filter_function_name_7390', 10, 2 );
function filter_function_name_7390( $role_list, $user_object ){
	// filter...

	return $role_list;
}
$role_list(array)
An array of user roles.
$user_object(WP_User)
A WP_User object.

Where the hook is called

WP_Users_List_Table::get_role_list()
wp-admin/includes/class-wp-users-list-table.php 581
return apply_filters( 'get_role_list', $role_list, $user_object );

Where the hook is used (in WP core)

Does not used.