B flat:
Left hand-Thumb and index finger
Right hand-index finger and first trill key
B natural:
Left hand-thumb, index, and ring finger
Right Hand-second trill key
C natural
Left hand-thumb, index, middle, ring, and pinkie fingers
Right Hand-index
This website offers multiple fingerings for each note
http://www.wfg.woodwind.org/flute/fl_alt_3.html