Complex sentence: For instance, for implementing a bandpass filter we need to modulating the signal to baseband, lowpass filtering the baseband signal and then modulating the baseband signal back to the center frequency of the bandpass filter.
Split into simpler sentences: For instance, for implementing a bandpass filter we need to modulating the signal to baseband. After using lowpass filtering for baseband signal, we use modulation and change the baseband signal to the center frequency of the bandpass filter.