I’m not sure I understand. To my understanding, you’re asking if performing a grouped convolution is the same as performing a standard convolution from each group of input channels to their respective group of output channels.
I believe the answer is yes. Having 4 groups would be equivalent to having 4 conv. layers side by side.
From the docs 4:

At groups=2, the operation becomes equivalent to having two conv layers side by side, each seeing half the input channels, and producing half the output channels, and both subsequently concatenated.