jQuery(document).ready(function($) { var modelField = $('select[name="acf[model]"]'); var specificationsField = $('select[name="acf[specifications]"]'); var specificationsOptions = { '40-200': ['Pump A', 'Pump B'], '40-160': ['Pump A', 'Pump C', 'Pump D'] }; modelField.change(function() { var selectedModel = $(this).val(); var options = specificationsOptions[selectedModel] || []; specificationsField.empty(); $.each(options, function(index, value) { specificationsField.append($('').attr('value', value).text(value)); }); }); });