Adding Allocated days in Board 1 to capacity management in board2

Hi,

So I have 2 boards.

Board 1 - It has multiple rows of campaigns and est days each will take
Board 2 - It has capacity management. Each row is a person. Has the total capacity for him/her. I want one column to automatically add all the days allocated to person X in Board 1. Then the final column is a formula which is Total Capacity minus added est days which will give out available capacity.

I understand that the formula column at the end is easy enough.

I want to check if there is anyway to add estimated days allocated to an individual …over multiple rows…then automatically add it in another board…

Any help will be greatly appreciated!