Попробуйте запустить этот код:
const data =
[
[
[
{name: "Michael Norman", house: "9", class: "3B2"}
],
[
{name: "Ronald Eyeson", house: "9", class: "3D3"},
{name: "Kingsley Buadi", house: "9", class: "3N"},
{name: "Lommo", house: "9", class: "3H"}
]
],
[
[
{name: "Michael Norman1", house: "9", class: "3B2"}
],
[
{name: "Ronald Eyeson1", house: "9", class: "3D3"},
{name: "Kingsley Buadi1", house: "9", class: "3N"},
{name: "Lommo1", house: "9", class: "3H"}
]
]
];
<div>
{Object.keys(data).map((key) => {
return(
<div key={key}>
{data[key].map((dataItem) => {
return(
<div>
{Object.keys(dataItem).map((innerDataItem) => {
return (
<h1>{dataItem[innerDataItem].name} </h1>
);
})
}
</div>
)
})}
</div>
)
})}
</div>