Hi Panya,
Greetings from Syncfusion support.
Currently, we do not have support for Resource Grouping in Gantt Chart. However, we have already logged a feature report for it. You can track its status from the below feedback link.
As we have already lined up some major features, we could not implement this support immediately. We will implement this and include it in any of our upcoming releases. Please cast your vote on this feature. Based on the customer demand we will prioritize the features in our upcoming road map.
Regards,
Monisha.