How to find the diagram of the nozzle in geomantic omen

When standing at the position where the hole is used, the last collection point of the running water can be seen visually, which is the nozzle.

In this picture, there is the first water inlet between the two mountains of Shegui, and the place where the running water can be seen behind is the second water inlet. In general, only the first water inlet is considered in geomantic omen.