Get the track used to filter by API twitter

I am using the twitter statuses / filter and track API with several search values to perform the search, and I want to know which of the parameters I put for the search is the one used, this can be done. The code that I am using is the following:

var filtro= "palabra1, palabra2, palabra3";
client.stream('statuses/filter', 'track': filtro},  function(stream) {
        stream.on('error', function(error) {
            console.log(error);  
        });
    stream.on('data', function(data) {
      console.log(data);});
});