One way to do it takes two steps.

Step 1 import the multi-channel MIDI file to Band-in-a-Box's Melody or Soloist track.

Step 2 Open the Melody or Soloist track multi-channel sequencer window.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
Clipboard56 Import MIDI File To Melody Or Soloist.jpg (70.63 KB, 114 downloads)
Import MIDI File To Melody Or Soloist Track
Clipboard57 Melody MIDI Sequencer.jpg (20.01 KB, 114 downloads)
Open Melody or Soloist Multi-Channel MIDI Sequencer

Jim Fogle - 2025 BiaB (Build 1128) RB (Build 5) - Ultra+ PAK
DAWs: Cakewalk Sonar - Standalone: Zoom MRS-8
Laptop: i3 Win 10, 8GB ram 500GB HDD
Desktop: i7 Win 11, 12GB ram 256GB SSD, 4 TB HDD
Music at: https://fogle622.wix.com/fogle622-audio-home