I want to use grep or map for the following refrence to find the child keys of 'Orange'.

My bold emphasis added.

Uses all the keywords from your question. But I suspect, as other have mentioned, that you are not asking the right question.

Note that this solution requires you to know that (1) Fruits is an array ref (2) Orange is a key to the 'Seasons' hashref, etc. All of which means you have a rather intimate knowledge of the data structure. Unless this is homework in how to use grep, map (and aparently foreach), there is something else you're trying to accomplish.