Is there a chance you send two API requests (one to get the details about the data set you are request and the other to get the values)? I tried using the fields= option in the dataValueSets endpoint and it doesn’t seem to be an option.
If the above is not possible, would you explain more about the use case? Normally, if you’re requesting dataValueSets, you’d already know specifically all the details of the dataset you are requesting the values from.