Not entire Classification Admin UI but 'Classification Root' folder can be accessed from NX.
Start NX from TC, In 'Reuse Library' navigator you can see the Classification Root folder.
Testing: NX 11 | NX 12 | TCIN
TC 11.2 | TC Vis 11.3 | AWC 3.2
NX 11.0.1.mp01 | SW 2016 | TcUA 11.2.3
What are you looking to accomplish?
If you're simply looking to classify individual parts in NX this can be done, with the part open in the session, by right clicking the node (class) in the Reuse Library under the "Classification Root" folder and choosing "Classify Part". You'll be presented with the following dialog allowing you to match predefined classification attributes with values in the part:
There was question - is it possible to have Classification Admin functionality from NX?
The answer - NO
In NX you can only have access to classification root for search or classify/
note: nx_access_tcclass license required for that
@alex_c, I understand the question, but you have to also question why it is necessary to see the UI in NX. Is the requirement to see the entire Classification Admin UI in NX, or would one small part suffice? One has to make certain assumptions when such an ambiguous question is asked, one of which in this case could be that the only requirement is just to classify parts - in which case, yes, this can be done in NX. Admittedly no one answered the question, which is 'no', the entire Classification Admin UI cannot be viewed in NX. That said, @hcl, may I ask why you need to see it in NX?