If your studio offers reservations for services like personal training, cold plunge, sauna, etc., you can create a schedule to view only these "classes."
Create a new classroom for your service (e.g. sauna) along with a layout to determine the capacity (the maximum number of people you can have booked in the sauna). Then, filter for the Sauna classroom at the top.
*Note: Make sure to create credit packages/memberships that allow for these reservations with the relevant Class Tags.