Alter the exposed filter value on change of other exposed filter value I wanted to do an interdependent select boxes using views exposed filters. So when i select the 1st exposed filter, the second once should filter itself based on first exposed filter value and this should happen dynamically. I tried a lot with form_alter but did not work. Any example or any suggestion as to how to go about it.
The easiest way of solving this, would be to use JavaScript. You need to have all the options available, and with JavaScript you can alter the options based on what's selected. Something like this:

$("#field-1").change(function(){
  if ($(this).val() == 'option_1') {
    var options = '&lt;option value="foo"&gt;bar&lt;/option&gt;';
    $("#field-2).html(options);
  }
});


The above is merely example code but illustrates the approach. You might need to do some work, in order to get the different options that should be available.