How do I adjust my shower knob to fully switch the water flow from the tub nozzle to the shower head?

I have a standard three knob shower with tub and the middle knob when rotated all the way only transfers some of the water to the shower head while the rest keeps pouring out of the tub nozzle. Can I adjust this? Is there any web site that y'all know about that illustrates what I need to do?How do I adjust my shower knob to fully switch the water flow from the tub nozzle to the shower head?There are seals or o rings in the switching control valve just like a regular valve. Take it apart and replace the seals. It's pretty simple.How do I adjust my shower knob to fully switch the water flow from the tub nozzle to the shower head?it is more than likely wore out check knob 4 tightness.