Currently I use the filter 'searcher_query_post_facet_filter' to add the following argument:
$args['query']['filtered']['filter']['range']['meta_price'] = array( 'from' => 30, 'to' => 70 );
Except when I do this the information I get back is different. The major thing is that I don't get any counts back. My Elasticsearch skills are still limited so I guess I use the wrong way of filtering.
This example is used for a price range slider so the range isn't static.