I cannot write one specific method as it depends on what you have as database... You can implement a short code for finding the nodes having minima from wall, I immagine you have an unstructured grid so you should know the topology and the links with the nodes at wall.

You can also have some already implemented option in the code. Alternatively, you can try to use tecplot to explore the values with probes.

I suggest to give more details about your data-set

You can have a look in this link:

https://www.cfd-online.com/Forums/fluent-udf/64326-how-find-cells-adjacent-wall.html

Basically, what this guy did is to define a UDMI value of 0 to all cells and a value of 2 for wall adjacent cells.

Then in processing you can run over all cells and look for cells where the value of the UDMI is 2.