I have a set of attributes which can be filtered with layered navigation. But when I set the filter in one category it should stay when I list the products in another category. But unfortunately I have to set the filter again when changing to another category. How can I solve this? Thanks
Basically you can save layered navigation selection in the session. For this you may use of the pre-dispatch events.
And update the
Mage::app()->getRequest()->setParam('color', 13); Where 13 is the value you have saved on the previous step from the request.
You also need to handle the params clearing and changing, so the values from the request have higher priority thet the same saved params in the session.