How to create category and subcategory selection in UITableView in iOS Objective-C

I want to create a table view with category and subcategory selection in UITableView with Objective-C for iOS but I do't know what to search and from were to start. The content of the category and subcategory are dynamic it can be one or more then it will be decided by web service result. and all category should be collapse on tap. It should look like this.

Any suggestion and help will be appreciated