How to Get Current Store ID from Current Scope in Magento Admin

If you wanted to be creative and native - you could use ifconfig in the layout XML and add a system.xml admin attribute - with a store-level scope definition.

Then you could conditionally include/exclude that XML block based on the store view.

Like all of Magento, the answer's in the source — all you need to do is go digging (or hop to then end of this post).

First, find the class for the attribute source

$source = Mage::getResourceModel('catalog/product')
->getAttribute('color')
->getSource();        
var_dump(get_class($source));
exit;

In modern versions of Magento, this should point to the class Mage_Eav_Model_Entity_Attribute_Source_Table, which is located at

#File: app/code/core/Mage/Eav/Model/Entity/Attribute/Source/Table.php
class Mage_Eav_Model_Entity_Attribute_Source_Table extends Mage_Eav_Model_Entity_Attribute_Source_Abstract
{
    //...
}

Next, we'll look for the definition of the getOptionId method on this class and/or it's parent classes. We'll find it in the Mage_Eav_Model_Entity_Attribute_Source_Abstract class

#File: app/code/core/Mage/Eav/Model/Entity/Attribute/Source/Abstract.php
public function getOptionId($value)
{
    foreach ($this->getAllOptions() as $option) {
        if (strcasecmp($option['label'], $value)==0 || $option['value'] == $value) {
            return $option['value'];
        }
    }
    return null;
}

Examining this method, we can see if works by foreaching over a list of options from the getAllOptions method. So let's look at this method's definition.

#File: app/code/core/Mage/Eav/Model/Entity/Attribute/Source/Table.php
public function getAllOptions($withEmpty = true, $defaultValues = false)
{
    $storeId = $this->getAttribute()->getStoreId();
    if (!is_array($this->_options)) {
        $this->_options = array();
    }
    if (!is_array($this->_optionsDefault)) {
        $this->_optionsDefault = array();
    }
    if (!isset($this->_options[$storeId])) {
        $collection = Mage::getResourceModel('eav/entity_attribute_option_collection')
            ->setPositionOrder('asc')
            ->setAttributeFilter($this->getAttribute()->getId())
            ->setStoreFilter($this->getAttribute()->getStoreId())
            ->load();
        $this->_options[$storeId]        = $collection->toOptionArray();
        $this->_optionsDefault[$storeId] = $collection->toOptionArray('default_value');
    }
    $options = ($defaultValues ? $this->_optionsDefault[$storeId] : $this->_options[$storeId]);
    if ($withEmpty) {
        array_unshift($options, array('label' => '', 'value' => ''));
    }

    return $options;
}

Ah ha! Now we're on to something. This appears to be the method that loads all the option information. Specifically, we're interested in

$storeId = $this->getAttribute()->getStoreId();

So, Magento gets the store ID for the options to load from the attribute. This means you should be able to do something like the following (replacing color and red with your own variables, of course)

    //get the attribute
    $attribute = Mage::getResourceModel('catalog/product')
    ->getAttribute('color');

    //set the store id on the attribute
    $attribute->setStoreId(Mage_Core_Model_App::ADMIN_STORE_ID);

    //get the source
    $source = $attribute->getSource();

    //get the id
    $id = $source->getOptionId('red');