Magento – Order Filter Layered Navigation

Layered navigation filters are rendered in catalog/layer/view.phtml template:

            <?php foreach ($_filters as $_filter): ?>
            <?php if($_filter->getItemsCount()): ?>
                <dt><?php echo $this->__($_filter->getName()) ?></dt>
                <dd><?php echo $_filter->getHtml() ?></dd>
            <?php endif; ?>

Here you can add checks for category and attribute id (replace the code aabove with the code below):

            <?php 
                $_categoryId = $this->getLayer()->getCurrentCategory()->getId();
                $_categoryFilters = array(
                    // top level categories
                    array(
                        'categories' => array(5,8,10),
                        'attributes' => array('color', 'size'),
                    ),
                    // second level categories 
                    array(
                        'categories' => array(6, 7, 9, 11),
                        'attributes' => array('manufacturer'),
                    ),
                );
            ?>
            <?php foreach ($_filters as $_filter): ?>
            <?php 
                $_found = false;
                foreach ($_categoryFilters as $_categoryFilter) {
                    if (in_array($_categoryId, $_categoryFilter['categories']) &&
                        (!($_attribute = $_filter->getAttributeModel()) ||
                        in_array($_attribute->getAttributeCode(), $_categoryFilter['attributes']))
                    )
                    {
                        $_found = true;
                        break;
                    }
                }
            ?>
            <?php if($_found && $_filter->getItemsCount()): ?>
                <dt><?php echo $this->__($_filter->getName()) ?></dt>
                <dd><?php echo $_filter->getHtml() ?></dd>
            <?php endif; ?>

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