digiKam - (tag) AND (not tag) using tag filter

[CryptoPaul]

I need to filter (tags) using the 'NOT tag' operator, for example, "(tag a) AND (NOT tag b) AND (tag c)".

I am able to achieve this using 'Advanced Search' then Adding two additional Search Groups and setting the relevant criteria there - However, that is a very convoluted process.

Is there a way this can be achieved more easily by the use of 'Tag Filters' - at the moment I don't see a way of doing it...

Paul