excel-like table with dynamic row grouping and column movement

I need to display data into a table where I can dynamically group rows just like below:

Then I can also move columns to interchange their positions. Interchanging them will recalculate by aggregating the values since the grouping is also changed like below (values are just example):

I can see that you can do manual merging on handsontable. How to do it programmatically because I need to calculate the values depending on the hierarchy?

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