Usually, C++ containers can be specialized via an allocator type which will override the default allocator for allocating elements and internal structures. To use a container in IPC shmem region, it must be allocated entirely inside this given region. Unfortunately, current implementation of tbb::concurrent_hash_map allocates some internal structures directly, bypassing user-specified allocator.
Thus, it is not possible to use tbb::concurrent_hash_map inside shmem region for now (though, it could be possible with few modifications to its code).
As for the scalable allocator, it can be used to allocate memory in the given region using "Scalable Memory Pools" community-preview feature, but it cannot replace standard allocator this way.