Reduce.js

groupsCalculated: (state) => {
    const buildNetwork = (connection) => ({ service_id: connection.service_id, login_id: connection.login_id });
    
    const connectionWithNetwork = (conn, net) => ({ ...conn, networks: [...conn.networks, buildNetwork(net)] });
    
    const buildConnection = (conn) => ({ name: conn.name, id: conn.id, networks: [] });
    
    return Object.values(state.all.reduce((acc, curr) => (acc[curr.name] ?
        { ...acc, [curr.name]: connectionWithNetwork(acc[curr.name], curr) } :
        { ...acc, [curr.name]: connectionWithNetwork(buildConnection(curr), curr) }
    ));
}