How to set MeshCollider CollisionFilter.GrounpIndex???

I want to use the CollisionFilter.GroupIndex as my game Camp,but the MeshCollider don't let me to change the GrounpIndex.Will you fix it or I can't use GrounpIndex of MeshCollider?

 

Can you share some more information about your use case? For example:

• Are you needing to change the group index for the whole mesh, or on a per triangle level?
• Is it something that happens continuously, or do you in principle only swap between two groups?

 

I want to use GrounpIndex as the camp,for example, blue camp and red camp are enemy camp,they have each army and building,the building are mesh collider,I can't even set its groupindex. As we know ,the CollisionFilter can quickly filter targets I want when I use physics query to search targets ,Include building make up of MeshCollider.