I want to create sublevel folder, Example we have category as folder and sublevel folders are category_updates,category_promotions like that, do you have any idea to get this??
It is as true now as it was 12 years ago. You cannot have sub-folders under gmail IMAP.
In fact, although the IMAP specs do appear to allow for sub-folders, I've not encountered any IMAP server that supported them.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.
roses are red, violets are blue. Some poems rhyme and some are a tiny ad:
a bit of art, as a gift, the permaculture playing cards