Here is another idea based on Charles’ idea.
Since the Magento Team has not yet allowed for configurable products to be allowed in grouped products, here is a solution to enable linking a simple product to its configurable parent products page.
This is good if you are selling sizes or colors and you want them to be able to select the size they want before they purchase. The only downside is that they will need to click through to the configurable parent product page before they purchase that item.
Here are the steps (I also created a video and posted it on my website since I couldn’t seem to upload it with this post [http://www.moderntheorie.com/tutorials.html]
1. Create a new attribute that will be applied to the Simple Products that are grouped in the grouped product
a. Go to Catalog > Manage Attributes
a. Click on the button “Add New Attribute” in the upper right-hand corner.
b. Create attribute called something like Parent Product URL* with an Attribute Code called parent_url
2. Go to Manage Attribute Sets
a. Add that attribute to the Default attribute set (or any attribute set you are using for these products)
3. Go to Manage Products and click on the simple product(s) that is/are a member of a grouped product (i.e. T-Shirt Small)
a. In the attribute settings area, find “Parent Product URL” and paste the parent product’s url in the text field.
4. In your source code, go to app/design/frontend/default/(yourtheme)/template/catalog/product/view/type/grouped.phtml
and replace it with the following code:
<?php echo $this->htmlEscape($_item->getName()) ?>
<?php echo "<a href=\""; ?>
<?php echo $_item->getparent_url(); ?>
<?php echo "\">"; ?>
<?php echo $_item->getName() ?>
<?php echo "</a>" ?>
4. Put your file and test
*Note: If you do this, every product that appears in the grouped product will need a Parent Product URL