Magento 2 layered navigation feature can help you to enhance the user experience of your store while handling onsite navigation with the attribute like price, dropdown and multiple select. Recently one of our client was facing an issue that some of its attribute (multiple select) is not showing in layered navigation after migration.

If you are facing this problem, then follow the below steps to resolve it.

f some of the attributes(multiple select) not showing in layered navigation. then follow the below steps to resolve it.

1. Open your Magento database and find attribute id in eav_attribute

2. run below query in your Magento database for change attribute backend_type  text to varchar

INSERT INTO catalog_product_entity_varchar
(store_id, attribute_id, entity_id, value)
 SELECT store_id, attribute_id, entity_id, value
 FROM catalog_product_entity_text
 WHERE catalog_product_entity_text.attribute_id = {{your-attribute-id}}
 AND catalog_product_entity_text.value is not null;

3. After inserting your attribute record, You need to delete the data from the text table

DELETE FROM `catalog_product_entity_text`
WHERE `attribute_id` = {{your-attribute-id}}

I hope I explained the problem and solution well enough :).If you too are facing problem while your Magento migration process then feel free to message in the comment box.