In the past I could display the imported layers in the GRASS toolbox within QGIS. This was possible under the tab "Browser" as you see in the image.
Lately I'm missing this tab. The QGIS version is 2.12.1 and the GRASS version 6. But I had the same issue with older QGIS versions.
How can I bring back the browser tab or what alternative option do I have to display the available layers of the mapset?