Chony,
The only thing I can come up with is that you set the S split point at F#2 and the L split point at B4. That would give you the chord accompaniment in the lower left up to F#2, and from there on to B4 Lower Voice choice.
You would need to choose sweet trumpet as Lower Voice of course. Now if you select no Voice for Upper, that leaves you the last octave without sound from the Tyros.
If your sampler is set to listen to only the Upper Keyboard (I guess channel 1 would do) then it will only receive the notes from the last octave from the Tyros keyboard.
If the Sweet Trumpet is out of his range in the "middle keyboard" between chord and top section, you can set the octave for the lower voice higher or lower in the mixer panel.
Best I can come up with, others may have better ideas. Let us know if it worked out will you.
Good luck,
John
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Have a nice day