Transmission Zeroes in Bandpass Filters

I want to design a dual band bandpass filter but I don't understand how to insert transmission zeroes in the passbands as I keep reading from several papers and books. I will be glad to receive insight from the forum please

Hi,
Could you share whichs bands are you interested in and/or what is the target (combine RX and TX, or connect antennas together or reject a band between 2 other)? Maybe there are better solutions, like a diplexer than play with transmission zeros.

thanks, my research is directed on the design of RECONFIGURABLE MULTIBAND BANDPASS FILTER please. and I wanna design a dual-band filter with microstrip resonators.