Hello,

I visited your site and saw the filter by width in the shop page: https://ibb.co/K6VHtG1. Same you can make the new attributes for example Test Attributes from Go to Products -> Attributes.

And enter the attributes values for example 600, 700, 800 from edit product page for each product or as per your need. https://ibb.co/5kVksXm.

And then Go to Appearance -> Widgets -> in the shop page widget area you can add the Woodmart woocommerce layered nav widgets and filter by attribute test attribute.
https://ibb.co/Dr7QjBF.

Best Regards.