The right control panel has three slots with buttons above and below. Pressing a top row button opens up a selection of symbols. Pressing a bottom row button rotates the triangle.
You would need to get all three symbols and the triangle positions right.
This is the low-spoiler guide for "Right embedded control panel" puzzle in Gibbous - A Cthulhu Adventure. Unlike in normal walkthrough, you get gradual hints on how to solve the puzzle. Click the big button below to see your first hint. If the hint contains a spoiler, you will be warned about it before clicking.