Get all data from each cell (each cell has input field)in repeating group?

Do you mean how to get the data from each input that you have in a repeating group?

Various ways, one is to have a button in each cell that when pressed will do something to save the value from the input.

Another is to use a free plugin called ‘Orchestra’ which will allow you to run a workflow from outside the repeating group on every cell in the repeating group to extract the value from the inputs.