Add custom ACF field to Woo Attributes

// Adds a custom rule type.
add_filter( 'acf/location/rule_types', function( $choices ){
    $choices[ __("Other",'acf') ]['wc_prod_attr'] = 'WC Product Attribute';
    return $choices;
} );

// Adds custom rule values.
add_filter( 'acf/location/rule_values/wc_prod_attr', function( $choices ){
    foreach ( wc_get_attribute_taxonomies() as $attr ) {
        $pa_name = wc_attribute_taxonomy_name( $attr->attribute_name );
        $choices[ $pa_name ] = $attr->attribute_label;
    }
    return $choices;
} );

// Matching the custom rule.
add_filter( 'acf/location/rule_match/wc_prod_attr', function( $match, $rule, $options ){
    if ( isset( $options['taxonomy'] ) ) {
        if ( '==' === $rule['operator'] ) {
            $match = $rule['value'] === $options['taxonomy'];
        } elseif ( '!=' === $rule['operator'] ) {
            $match = $rule['value'] !== $options['taxonomy'];
        }
    }
    return $match;
}, 10, 3 );

This goes to functions.php and afterwards will be visible in Custom Fields where you set where the custom field should be visible