Meanwell Led driver: internal 3-in-1 dimming circuit
@Transistor had made a great explanation about Meanwell's clever 3-in-1 dimming technique.
Here's an excerpt from one of my old designs -- inspired by Meanwell, but not the copy of it:

The circuit may be different, but the functioning is the same as Meanwell's.
C305, R314, and R315 form a 1st order LPF /w voltage divider to decrease the 0-10V output down to 0-3.3V for MCU (There's a 3V6 Zener at MCU side, which is not shown here). Removing R315 only gives a 0-10VDC signal.