Using sublevels that has their own sublevels?

As the title suggests - is this possible? It seems to not work out of the box in UE4, but I haven’t been able to find any solid information/documentation on this.

Can anyone enlighten me on this?

Thanks in advance!

As far as I know that is not easily possible. But would be there any benefit if you could load levels that have their own sublevels ? Normally you use one persistent level and stream or load in what you need.