Cven I isolate all the inside related group, but still I can not get a correct result, is that a bug or something I need to tweak? thanks for the help in advance.

Try the latest daily builds - there was a bug where the groups were not preserved correctly with edge detail on

thanks cwhite, but when I do it in build 376, it kind of solved the problem I asked, but I found another two issues:
1. if I lay down multiple RBD material fracture nodes, i can not isolate inside outside group correctly
2. those new created faces have some unexpected attribute default value, lets say I want those new created attribute default set to 0

The outside group issue is fixed in tomorrow's build

inside group works well with production build .416
outside group seems to just include all the primitives.

in the meantime “!inside” will do the trick.