Data passed to other pages via hyperlink is being cut off

Answer 1

You need to encodeURIComponent the value for category before using it in a URL.

$('#BusinessCreateCategory').change(function(){

    var category=$('#BusinessCreateCategory').val();
    var encoded = encodeURIComponent(category);
    window.location.href='getbusinesssubcategory.php?category='+encoded;

});

Ampersand is a special character that garbles the URL you are trying to pass. Encoding the value should allow you to treat it as a single value.