@AbhishekC1725 please check the below URL. Node level dpage is for meant for whole node level application that covers all the requestors. So as node level data page can't get a specific requestor access as it is not running on a particular requestor level, we explicitly provide access group for it's access.
Thread, Requestor we need not specify any access group. But for the node level, we need to specify the same. Reason: Node level data page acts as a separate requestor that runs in its own execution stack, which is different from any requestor user.
Please go through the below link for your better understanding