Reply To: Multiple search widgets

To apply the code multiple times, you will have to rename the function, like this:

add_filter( 'asp_query_args', 'asp_include_only_parent_ids2', 10, 2 );
function asp_include_only_parent_ids2( $args, $id ) {

Putting a number after the function name will work just fine. Make sure to change the function name in the preceeding add_filter statement as well.