I came accross an interesting book called “A Dictionary of German Synonyms” by RB Farrell.
It discusses the differnce in meaning and usage between words with similar meanings. I would say that it is only of interest to those of B1 level or at least approaching B1, however there are often posts on the forum about the subtle diffences between words so it may be of interest to some people.
I think the book is out of print but it is avalable cheaply on the secondhand market especially if you don't mind about perfect condition.
