Create list of things from "multiple" RepeatingGroup fields

Hi All,
I am new to bubble.

I have a repeating group shows Companies and a dropdown shows list of Contacts of each Company.

When Save button is clicked, I need to save only the checkbox checked Company and corresponding Contact in a join table. Note: Contacts may be manually selected in dropdown or set as Default Value.

What is the standard method to attain the result?

When checkbox is checked, I could save Company in a State. But I couldn’t access the Contact dropdown value. Is there a way to loop the Repeating Group and if the checkbox is checked, get the values of all the fields in the cell?