If your mind map was deleted accidently, there are two ways for you to recover your mind map.
1. Recover from Recently Deleted
1) Launch Xmind for iOS;
2) Enter Browse > Location > Recently Deleted;
3) Long press the file you want to recover > Recover.
2. Recover from File Cache
1) Launch Xmind for iOS;
2) Enter Settings > File Cache;
3) Tap the file you want to recover > Retrieve.