Last modified: 2014-04-01 00:31:04 UTC
There should be a close section link on the bottom of each collapsible section to close this section. The current way is to scroll all the way up to the section heading which can take some time when the section is long.
Prioritization and scheduling of this bug is tracked on Mingle card https://wikimedia.mingle.thoughtworks.com/projects/mobile/cards/1821
We used to have this and removed the link due to data showing low usage. See I06aca5c6237ffe340eb952f59d11212e51c04e72 for background. The mobile team currently has no plans to implement this for Wikimedia sites. We are thinking about things such as fixed headers however which would allow you to access the search and main menu from anywhere on the page.