Press Tab to show mini map. Hold Alt while holding tab to show players list. Use mouse scroll to zoon in/out.
If you travel long distances (tens of thouthands blocks), this mini map may cause FPS drop on low-end system. Also all sections of map are kept inside RAM and video memory.
To clear them from memory just disable/enable.

Enabled

Override starting scan Y level

Scan from Y:

For custom dimensions (however this setting affects all dimensions).

Example: [{ "x": 100, "z": 200}, { "x": 200, "z": 300 }]