Payment Field: How can I separate products in sections and filter them?

2. can i maintain a separate sections for the products and also filtering method to display list of products?

If you want to show or hide products depending sections selected, then you will need to set them up in normal fields, using radio buttons, drop downs or check boxed: 

You will need to also change the current settings on your payment field, and will need to use a widget too, the Form Calculation widget will help you to get the total amount and pass it to your payment field. 

As I can understand, you want to separate your products in sections, then show them separately, here is a guide that may help you, so for example, if a category or section is selected the proper products will be displayed: How-to-Show-or-Hide-Fields-Base-on-User-s-Answer

Here is also a guide that will help you to pass the calculation value to the payment field: How-to-pass-a-calculation-to-a-payment-field

If you need some help when applying this to your form, please let us know, we will be glad to help you. 

I have also a sample form to show you how that will work, you can take a look here: https://www.jotformpro.com/form/53297060437962 

Feel free to clone it, this guide will help you: How-to-Clone-an-Existing-Form-from-a-URL