How to create custom index for a material group?

I have to create an index for a group of materials (for example resources or intermediate product), but I have no idea how to go about it (I am a complete beginner - Dynamic AX is not my expertise). Is there a way to do it via x++? If so, how can it be done?

What does that mean? Are you talking about index on a table?

Please elaborate.

The thing is, I’m not entirely clear on that myself. From what I’ve gathered it’s supposed to be some category to serve as a point of reference, to be viewed in BOM (as in “Iron (resources)”).

Still not clear. May be an example or a screen shot.

I found some blog post about dynamic grouping. It may be what my client had in mind, but I would need to achieve it in x++. Here’s the link to the post:
community.dynamics.com/…/dynamics-ax-2012-exploring-the-dynamics-grouping-in-dynamics-ax-ssrs-reports

How is it related to your original question?