How to make localized pinching layers?

Hi! I'm trying to pinch out layers in a model of an open pit. I've found how to pinch out layers in 3D configuration by adding a number of layers between two fixed layers, but I need to pinch out layers only in the sector of pit and not in the complete layer and I don't know how to do it and if it is possible to do in FEFLOW (I hope that it can be done).
Help me please!  :-\ :-\

Hello,
Currently, if without using the "3D layer configuration" or using the "TetGen mesh generator", you cannot trigger the options for the unstructured mesh to "physically" pinch out the layers at the same position.

Here is an attached example that my Slice 2 has an elevation of 30m, and Slice 1 is 50m at the beginning.

Without using the "3D layer configuration", I manually changed the elevation of a pit area on Slice 1 to 30 m, it can trigger the processing option for the classic approach "[b]layer-based model[/b]" (with a very thin thickness), so-called [b]"minimum distance"[/b](e.g. 0.1 m) between Slice 1 and Slice 2. That means, in the end, my pit area on Slice 1 has an elevation of 30.1m.

Best,
Jintao