If you notice that your Calculation fields are unavailable, it is because Calculation fields cannot be used between different record types. However, Calculation fields can consist of fields from other record types.

So you cannot use a Request: Calculation field in a Review template, but you can use a Review: Calculation field and build the Review: Calculation field with Request fields in the formula.

Using these steps will make the same calculation occur, the issue lies in the definition of the actual Calculation field.