Object dimensions

I like to thank you for your assistance. I don’t know if I should start another thread for this next part. I’m putting 2 doors on the upper have. There will be a shelf on the upper half behind the doors. What’s the best way to show this

thanks
Mike

I attached the file. First guideline is the top of the shelf, second guideline is the bottom of the doors, third guideline is the top of a shelf.
vanity3.skp (85.7 KB)