How can I limit the current drawn by a Li-Ion battery pack BMS?
BMS chips are typically for protection from over and under charge... You still need a properly designed Lipo charger that is CC/CV.

BMS systems typically just have FET transistors that disconnect the battery from the circuit in the even of over or under charge.

Unless you are using the term BMS wrong, they are not intended to be used as a charge controlling device or a primary charger, just a safety to keep a pack from exploding during or after charge.