a
без атрибута href. button1@onclick => $('.your-element').slick('slickFilter', '.category1');
button2@onclick => $('.your-element').slick('slickFilter', '.category2');
button3@onclick => $('.your-element').slick('slickFilter', '.category3');
elem.value = iss.replace(/\s/g,'').replace(/(.{4})/g,"$1 ").trim();