try to add MDTF taxonomy only widget. Choose "products", save widget, then
Add next in fields
http://rehubdocs.wpsoul.com/wp-content/uploads/2017/01/self.png

and choose your attributes in taxonomy options. This must work.

In MDTF settings - advanced settings, you can play with next fields
https://www.screencast.com/t/hmycY1QykzE

Also, author told that dynamic recount option in widget settings can slow
down a lot.

To be truth, i never was successful to make MDTF fast on sites with many
posts

So I love rehub and have dedicated a good amount of time to optimize it. There is something that has been killing me and I think a lot of people would like to know. Can   (MDTF) handle large shops and if so how large 10,000 products? 50,000 products a million? So I created a junk server just to get the answer.  I generated 500 vendors  and will continue to upload random product divide amongst them. I also created 10 attributes with a random number of terms. each term is archived. Here is where I could really use a hand. I don't understand how to set up the MDTF very well. could you logon to the site and use the existing random attributes to throw together a MDTF filter for woocommerce show we can test how it does with lots of products

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