If you want to specify different affiliate commission rate for different WooCommerce products then use this documentation.
Step 1 (Download and Install)
Download this addon plugin and install it just like any WordPress plugin.
a) Upload the “affiliate-woocommerce-advanced-addon.zip” file via the WordPress’s plugin uploader interface (Plugins -> Add New -> Upload)
b) Activate the plugin through the “Plugins” menu in WordPress.
Step 2 (Edit the Product)
Edit the WooCommerce product in question (where you want to use a different affiliate commission rate)
Step 3 (Configure the Commission Value)
Find the “WP Affiliate Platform” section and specify the commission rate value (see screenshot below):
Save the product.
Now, when an affiliate referred customer purchase this product, the plugin will give commission according to the rate you have set in the product configuration.