Awesome, thanks Trevor! This looks like it’s definitely on the right track! I’ve tried using the filter with the following foreach code and while it does remove all the unwanted terms, it doesn’t display all the wanted terms. At the moment it’s set to display as a checkbox list, if I change it to a dropdown it works as expected, but I need it to work with the checkbox format. Any idea why it doesn’t?

foreach($input_object['options'] as $key => $option) {
 if ( !in_array( $option->value, array(‘option-a’,‘option-b’,‘option-c’) ) )
  unset($input_object['options'][$key]);
}

The full code is below. They both work as dropdowns, but neither work correctly as checkboxes. They output some options, but not all of them. It might be to do with how I removed them from the array, is there a better way to do it?

function filter_input_object($input_object, $sfid) {
	if( !in_array( $input_object['name'], array('_sft_age_group','_sft_health_problem') ) )
		return $input_object;

	if( $input_object['name'] == '_sft_age_group' ) {
		foreach($input_object['options'] as $key => $option) {
			if ($option->value == '') {
			} elseif ($option->value == 'prenatal') {
				$option->label = 'Early Childhood (<5 year)';
				$option->value = 'prenatal+infant+pre-school';
			} elseif ($option->value == 'primary-school') {
				$option->label = 'Primary School (5-12 years)';
			} elseif ($option->value == 'early-secondary-school') {
				$option->label = 'Secondary School (13-17 years)';
				$option->value = 'early-secondary-school+late-secondary-school';
			} elseif ($option->value == 'early-adulthood') {
				$option->label = 'Young Adulthood (18+ years)';
			} else {
				unset($input_object['options'][$key]);
			}
		}
		return $input_object;
	}

	if( $input_object['name'] == '_sft_health_problem' ) {
		foreach($input_object['options'] as $key => $option) {
			if ( !in_array( $option->value, array('option-a','option-b','option-c') ) ) {
				unset($input_object['options'][$key]);
			}
		}
		return $input_object;
	}
}
add_filter('sf_input_object_pre', 'filter_input_object', 10, 2);