Using a level shifter with 1.44 inch TFT 128x128 GLCD ILI9163 and a 5v Pro Mini

For a beginner, it appears that there is some conflicting information, so please help me understand. doesn't the pot only control the current? how can that be used to control the voltage
I bought two items. the first based on your recommendation:,

You are saying you are using a poteniometer.
I purchased a 10k ohm trimpot today. Can this work? also can the ground be shared with the ground from the same ground pin from the 5V stuff, or do i have to use a separate ground on the arduino

and a second using a 3.3 volt voltage divider that handles a 2V drop.

how are either of these items to be wired in?

thanks
SSOI