It seems like you're trying to add a field to the table and a form, and then you want to create a form rule to hide or show sections based on its value.
To accomplish your goal without a script, users will need to be able to open the record to edit. Create a copy of the form you want to use. Customize the form, and for each of the form elements except the one you want to control the view, select the checkbox that says "Read-only (even when used for data-entry)."
Add your sections and save the form. Go back into customize and add dynamic form rules that will show and/or hide sections based on what the user chooses in the dropdown.
That should do the trick.
