When working with 3D data in ArcGIS Pro, it's important to be able to effectively view and analyze negative Z values. Here's how you can do it:

1. Enable 3D visualization: Start by enabling the 3D scene view in ArcGIS Pro. This will allow you to visualize your data in three dimensions, including the Z values.

2. Adjust symbology: Once you have your 3D scene set up, you can adjust the symbology of your data to better visualize the negative Z values. For example, you can use different colors or symbols to represent negative Z values, making them stand out in your visualization.

3. Use transparency: Another useful technique is to use transparency to visualize negative Z values. By making the features with negative Z values partially transparent, you can see how they relate to other features in the 3D scene.

4. Adjust elevation exaggeration: Elevation exaggeration is a useful tool for emphasizing the vertical aspect of your 3D data. By adjusting the elevation exaggeration, you can better visualize the negative Z values in relation to the rest of your data.

5. Utilize 3D analysis tools: ArcGIS Pro provides various 3D analysis tools that can help you better understand and analyze your data, including negative Z values. These tools can provide valuable insights into the spatial relationships and patterns within your 3D data.

By following these steps, you can effectively view and analyze negative Z values in 3D ArcGIS Pro, helping you gain a deeper understanding of your GIS data and make more informed decisions. Remember to always consider the context of your data and the specific requirements of your analysis when visualizing negative Z values in 3D.