I have 1 attribute (dropdown) that i use in layered navigation. Is there a way i can merge/combine multiple dropdown options/labels to just 1 label/option in the layered navigation? I have tried mydomain.com/category1/?attribute1=option1&attribute1=option2 but i get not the results i want (it only shows products with option2).

For a complete picture: I use the filter for suppliers (my own products, dropship and 3th party products). People can filter by supplier but the problem is with the dropship suppliers. I want to combine those suppiers with my own shop/products filter so those products show-up under that filter and don't have their own filters.

I can solve the problem with hiding the dropship suppliers from the navigation with a 1x1 blank image but that won't hide the product count (i can disable the counter if that is needed but i like it when i can still use it.) I know there is a extension that will do almost the same but i don't want a extension and that extension is not hiding the attribute options i want to hide.