Using the Break Back function
Overriding Break Back in processes
Application database > Processes tile > select process >
> Process setup > Data Entry & Submission Rules section) > Gross & IC amounts > 
Application database > Processes & Workflows > Processes > select process >
> Process definition > (Data Entry & Submission Rules section) > Gross amounts & IC > 
Overriding Break Back in matrices
Excel > CCH® Tagetik >
Design > select form >
Matrix > Matrix options > Form - Break back