Soloing Over Cmi7-F7-BbMaj7

Cmi7

Hinting at a Cm9 (D note), chromatically descending to the A, which is the 3rd of the F7.

F7b9

A diminished arpeggio suggests an F7b9 (F#/Gb), then chromatically lands on the 5th of the Bb Maj7 chord.