Using AG Grid, we see how row grouping can be used to transform relationship-related data, in this case gift card purchaser and recipient, using grouping. A similar effect for sub-details can also be achieved using the Master/ Detail capabilities of many data grids, including AG Grid. Other grids do have grouping features available, so it's worth researching your favourite grid to see if grouping is supported and whether it is a free or paid feature.
Rather than use the Elastic UI form controls showcased in the sample data grid example, I've showcased the Autocomplete and Select controls from MUI to promote reusable alternative component libraries to Elastic UI, bearing in mind that developers may need to adhere to alternative UX themes such as Material.