Can you operate the hand shower and the main shower head at the same time

The large handle is the main control handle, it controls water temperature by turning left/right and water volume by turning up/down. The small knob is diverter, which controls water running out from the rain head or another rain head. Only when you turn the diverter to the proper position between two functions can the two functions work simultaneously. But in this case, the water flow of each function won\'t be as powerful as it works alone.