g-Platform offers variety of noise attenuation modules and other procedures that work in a loop like spherical divergence, decon. We can find in a list or via find module searching. Add NA module inside the seismic loop, then modules connects to each other automatically, but if we want to make our own connection, so there is an option to disconnect modules (see module settings->auto-connection). Almost all modules are able to calculate difference gather (see settings tab):