Show/Hide Page Rulers ⌃⇧R ⇧2⃣ – Logic Pro keyboard command of the day

  Show/Hide Page Rulers  ⌃⇧R ⇧2⃣

Shows or hides the page rulers. Only works when in Page View.

Logic Pro score layout overview – Apple Support

Show Page Rulers: Displays horizontal and vertical rulers that make precise layout tasks easier.