How to create different Size filter option for each group of collections?

Assume that your store has three collections: Tops, Dresses, and Shoes.

- Tops and Dresses collections have the following Cloth sizes: XS, S, M, L, XL, XXL, etc.

- Shoes collection has the following Shoe sizes: 35, 36, 37, 38, 39, 40, etc.

If you need to display Cloth sizes filter option in the Tops collection and Shoe sizes in the Shoes collection, you could follow these steps:

Step 1: Add tags to product

- Go to Tops / Dresses products and add tags with the prefix: "cloth-size:"

- Go to Shoes products and add tags with the prefix: "shoe-size:"

Step 2: Create filters for Tops & Dresses

-  Create a specific filter tree for Tops & Dresses collections

You need to select Tops and Dresses in the field Collections that use this filter

Add Cloth size filter option

Here you must turn on the option Using prefix and enter "cloth-size:" in the field Filter the tags by a prefix

Step 3: Create filters for Shoes

You could do the same step to create the filter tree for Shoes

Add  Shoe size filter option

Step 4: Check the result in the storefront

- Tops collection

- Shoes collection