I use the symbol context snippets for documentation snippets. The snippet $BaseClassName$ works quite good inside a class context but does not work outside the class context.
<using snippet with $BaseClassName$ does not work here>
class CFoo : public CBar
{...
<using snippet with $BaseClassName$ works here>
Ok, there is no class context if I am outside the class, but maybe you can provide a "Document Class" feature similar to the "Document Method" and the $BaseClassName$ works there.