Spreadsheet Model Function Question - ' IS_CONNECTED_BY' Function

I'm looking for a way to depict relationships/connections between objects in a Spreadsheet Model in order to protect them from Reorg destruction.  

I've come across the 'IS_CONNECTED_BY' function and would like to understand how it is used and what it depicts in the Spreadsheet Model.  Also, I've tried using this function but cannot get it to work.  

Any insight or guidance would be well appreciated.

Thanks, 

Ryan