For audio tracks, you can access the Tuner using the Tuner button in the Smart Controls menu bar. For details about the Tuner plug-in, see Enable Complete Features is selected in Logic Pro > Settings > Advanced, you can change the layout for a Smart Control, map screen controls and edit mappings, rename screen controls, and assign external controllers to screen controls in the Smart Control inspector.
Tap the screen control name, then drag the slider left or right to adjust the screen control setting.
Download the guides:
Logic Pro User Guide: PDF