Mantragora posts a solution for finding primitives with similar attributes in Houdini by creating a tool using the Houdini HDK. This comes as an answer to a question that was posted on a forum.

Although you are able to accomplish the same task with a simple VOP example, Mantragora took it a step further and created a tool with the HDK in C++.

If I have attribute on geometry , and some grouped primitives (let’s say 3). How do I find other primitives that have the same attribute value like those grouped ones ?

The HDK is a comprehensive set of C++ libraries for Houdini that are the same libraries that the Side Effects programmers use to develop the Houdini products.

With the HDK, you can create plugins which customize different areas in the Houdini interface such as creating custom expression functions, add custom commands, add custom operators, add outputs to a non-standard renderer, or add custom lighting effects or atmospheric effects to the renderer.

If you are interested in the original forum post, you should be able to find it here:forums.odforce.net/index.php?/topic/15751-how-to-group-primitives-by-comparison/#entry96747 You are also able to find the attached example scene for houdini and the code that you are able to compile on your own.