How do I make subform row items appear only once in an HTML table in zoho creator snippet pages?

How do I make subform row items appear only once in an HTML table in zoho creator snippet pages?

I have attached a screenshot. Category fields are fetched from a subform rows and rows can contain similar categories. I want to show category only once in this table with its count in head count. For example Engineer - 2 and not as it is currently being shown. Web