Depends on your knowledge. Improvising on something like this is not for the faint of hear whom has no music theory knowledge... but Do you know your major and minor pent scales inside out up down forward and back?
If so, a starting point atleast... would be to write out the scale that goes with each of those chords... and then simplify each scale into any pentatonic scale that they might contain (if they do).
So let me tear this apart quickly...
On ALL of these chords, you could start by just improvising on the 3 or 4 chord tones of each chord, but that won't last...so here's a pentatonic analysis, from just one persons point of view...;-)
F#/D = D E F# G A B C# D (d major scale)
So on that chord you could play D major pent, or Bm pentatonic (both the same 5 notes, which ever you 'think' is easier)
Gm7 = G A Bb C D E F G (G Dorian scale)
So on that you could play G minor pentatonic.
Am7 = A B C D E F# G A (A Dorian)
So on that you could play A minor pentatonic.
Dm7 = D E F G A B C D (D Dorian)
So on that you could play D minor pentatonic.
EbMaj7 = Eb F G Ab Bb C D Eb (Eb Major scale)
= Eb F G A Bb C D Eb (Eb Lydian, more beautiful, and the only non-diatonic example so far)
So on that you could just play Eb Major Pentatonic, or C Minor pentatonic (both the same 5 notes, which ever you 'think' is easier.)
Em9 = E F# G A B C# D E (E Dorian)
So on that you could just play E minor Pentatonic
Bm7 = B C# D E F# G# A B (B Dorian)
So on that you could just play B minor pentatonic
Bbmaj7 = Bb C D Eb F G A Bb (Bb Major Scale)
= Bb C D E F G A Bb (Bb Lydian, more beautiful)
Gm7 = Same as previous Gm7
Thats where i would ultimately start if i really wanted to study this tune. I might even look through the above info and see which notes are shared between multiple chords, so that they can be put to easy use..
If Pentatonic gets to easy for that (unlikely), then ad the 2 notes to make it its diatonic scale which i outlined. But in this song, your not likely to get more than 2-4 notes PER chord in most spots, and so trying to improvise with 7 notes, and pick only 2-4 in no time at all, can overwhelm.
However, on that note, this whole message can overwhelm, because i have no idea if you know what a pentatonic scale is! hehe ;-)
My youtube channel is www.youtube.com/FusionJamTracks
come and say hi anytime. I have Jam Tracks that could help you with each of these individual chords.