few more details might help. You can transpose the playable range on the keyboard within the BBC app. for each instrument (but can’t extend it to my knowledge) and in the Dorico Expression Map, you can also set the location of middle C for each EM. I assume you’re using John’s Playback Configuration from the BBC website? If you’re talking about all instruments then it would be interesting to know if you’re getting the same with other software using the BBCSO.
Yes, but if I transpose I lose the lowest notes. The app clearly shows what the ranges are, so I guess they can’t be expanded 
I get the same result in Cubase.
I’ve written Spitfire audio about it…
Thank’s for answering 
Would you let us know what Spitfire reply please, thanks.
They replied “There is no issue here, the Bass in BBC SO only stretches from C0 to F2.”
So - bass playing in the upper octave in BBCSO is not possible 
I wasn’t actually quite sure what your question meant at the time but now it’s clear you’re referring specifically to the strings double bass --when I look at this patch then it’s clear the range is C0 to F2 as the playable notes are in white and, unlike with something like VSL, you cannot expand on the default by stretching it.
I do myself find the BBC range in general somewhat restricted in some cases and have to rewrite some notes which can be played perfectly OK by musicians for other libraries for instance (and I’m talking only of proper sampled VST’s of course and not something like NotePerformer) but have not been recorded by the BBCSO if I want to compare mockups.
G3 is the generally accepted upper range for orchestra section double bass parts, though there are a few occurrences of A3.
Of course soloists can and do play a lot higher, but the clue is probably in the “SO” part of the library name.
Stopping at F3 instead of G3 seems a bit miserly, though.
of course the musicians who record for the top libraries are likely to be rather better than your average second desker. In writing for real musicians, you obviously have to decide whether to torture them or not.