There is nothing, as you probably have already get to know in the Explorer or API, that's why you are posting here now. If there would be sth like this it would be here or somewhere else mentioned.
I think with a bit coding you will be able to realize such func./widget by urself.
I dont know the pure JS component there, but i think its based on query params. This should be realizable as well in GXT. Of course it is quite some work efforts needed to implement it.