Hello @vishakhanehe ,
At the moment I do not have any example to accomplish the exact what you need. It needs to be implemented in several parts & requires a professional to work on it.
For example, to add an additional input field in the vendor dashboard you can see this article: https://wedevs.com/108107/how-to-add-extra-field-on-vendor-settings-page/
You can use these filters to modify the vendor earning, commission:
apply_filters( 'dokan_get_earning_by_product', $earning, $product, $context );
apply_filters( 'dokan_order_admin_commission', $saved_fee, $order );
apply_filters( 'dokan_get_earning_by_order', $earning );
This discussion here will give you an idea of how you can add additional fees while only using WooCommerce: https://stackoverflow.com/questions/38382278/add-fee-based-on-specific-payment-methods-in-woocommerce
Please get in touch with a developer to work on it or you have our paid customization service here.
Thank you ??