title: Multiple dependent dynamic dropdowns with repeating column dropdowns in Google Sheets
body: <p>The Google Sheet I have uses code made by user <a href="https://stackoverflow.com/users/5372400/max-makhrov">Max Makhrov</a>, code <a href="https://gist.githubusercontent.com/Max-Makhrov/060c21da4f280b6faac82337dadb16e5/raw/751a733db265535b6aebf0d50515169d6634875b/Dynamic-Dependent-Drop-Down-Lists.js" rel="nofollow noreferrer">here</a>, to make multiple dependent dynamic dropdowns in columns D-F (for location) and columns H-L (for objectives &amp; activities) in my sample sheet <a href="https://docs.google.com/spreadsheets/d/1Mjx9JNtsGvajG6gMi2ZtQPlWcXV9LIJCMb9B0A5INJI/copy" rel="nofollow noreferrer">here</a>.</p>
  
  <p>I would like help to modify the script to do two things:</p>
  
  <ol>
  <li>Whatever activity is selected from the dropdown menu in Column I, I would like the same dropdown menu options to be available (to repeat) for columns J-L. As you can see I found a way to do it, but to me it seems clunky and not ideal, and leaves too much room for errors. Users should not select the activity twice, but I've put conditional formatting in to flag that if they do. However:</li>
  <li>Ideally, but less importantly, if the dropdown menu items could still repeat for columns J-L but once an activity is selected in previous cells, that option is removed from each of the following repeated dropdown menus in additional columns, up to and including column L. This would help avoid accidentally repeating an activity.</li>
  </ol>
  
  <p>NB: Reference question "<a href="https://stackoverflow.com/questions/21744547/how-do-you-do-dynamic-dependent-drop-downs-in-google-sheets">How do you do dynamic / dependent drop downs in Google Sheets?</a>"</p>
  
  <p>Thank You!</p>