How to calculate function that get remining days from vacation and minus them from 21 days also included week end days by app sheet

How do I make the data that my user adds to my Google Appsheet app in one of my screens that stores data in one of my tabs in my data source (Google Sheets) and also update another tab of the spreadsheet in my data source?
For example, my user has entered data for a “new proposal” in the “Proposals” window, but I want it also to update the information in the “Update” window.
I’ve already tried to create an “Action” and a bot to automate this and haven’t succeeded.
As I am making a reference (REF) between the data in each tab of the spreadsheets, I expected that when I included or updated the data in one, the other would be updated as well.