It may be more complicated when you're trying to make a TRS balanced connection, because some have internal line resistors( god only knows why, you might not need em) but for a TRS to 2xTS its pretty simple.
I doubt you will find a diagram for something like that, but the sleeve is ground, ring is negative and tip is positive.
The right TS is GND/Positive and left TS is GND/Negative.
Then connect the TS and TS ground to a common TRS ground.