Assign more than one frequency (1D and/or 2D) to the same atom

There should be a way to not only define the assignment of a 1H or 13C frequency for a specific atom from *either* the 1D *or* one of the 2D spectra. But rather, one should be able to assign the 1H frequency in 1D, COSY, HSQC and HMBC etc. and the same with the 13C.