SOURCE

let arr = [
    {
        name: "/",
        meat: {},
        children: [
            {
                name: "home",
            },
            {
                name: "home2",
            },
            {
                name: "common-components",
                children: [
                    {
                        name: "form-component",
                    }
                ]
            },
            {
                name: "multilevel-menu",
                children: [
                    {
                        name: "second-menu",
                        children: [
                            {
                                name: "third-menu",
                            }
                        ]
                    }
                ]
            }
        ]
    }
];

function flattenChildrenReduce(arr) {
    return arr.reduce((result, item) => {
        result.push(item);
        if (item.children) {
            result = result.concat(flattenChildrenReduce(item.children)); 
        }
        return result;
    }, []);
}

const flattenedData = flattenChildrenReduce(arr);
console.log(flattenedData);