XMind 8 offers 16 map structures, e.g. Tree Chart, Org Chart, Timeline, Matrix, etc. Normally, the location of the topic is determined by the structure you choose. However, there are a few ways to move topics freely.
Press "Alt" key and move the main topic
If you’re using the default Map structure, this trick can help you free position the Main Topic. At present, this trick only works for the main topic. Use the Command key on macOS instead.
Press "Shift" key and move the floating topic
Pressing the Shift key and moving the floating topic you can position the floating topic anywhere without linking to other topics. Moving a topic linked with other topics, their links will also be canceled.
Allow Free Position
After enabling the Allow Free Position feature by clicking Modify > Allow Free position, you can freely move the Main Topic without pressing the Alt key.
After clicking Modify > Allow Overlaps to enable the Allow Overlaps feature you will allow topics to overlap each other.
If your mind map tends to get messy, simply click Modify > Reset Position to reset your topics position.