Old style signal processing?
there is a relationship between filterbank analysis and the STFT analysis, but it is not an identity.

perhaps it can be identical, where for filterbank, you are slicing the frequency domain into band slices and for STFT you are slicing the time domain into windowed segments (in audio we might call them "grains" or maybe sometimes "wavelets") in time.  but to make the two identical will require some thinking.  the BPF can't be simple regular-old BPFs.