Please follow the steps below to create a folder on local drive:
1) Launch XMind for iOS;
2) Enter「Browser」->「Location」;
3) Tap「On My iPhone/iPad」->「XMind」;
4) Slide down the page and then you can see a hiden tool bar;
5) Tap「」icon to create a new folder.
(Or you can long press the blank on the XMind folder to create a new folder. )