I have a question in 'Collect' which asks to pick multiple vegetation choices 'tick all which apply' option but when each option is selected I want a 'dropdown' or similar to select a percentage of that vegetation type. What is the best way to do this?
I would go with a seperate follow-up question, referencing the previous choices.
e.g. "In the previous question you selected vegetation type A. What is the percentage of this?" (in the "relevant" column you can define that this question will only be asked if option A was selected) and so on for each selected option.