In fuzzy mode, using ' '(space) as the and operator, the candidate lines should fuzzily match all the substrings separated by space.
e.g., input abc def gh,it can match the following strings:
...a.b.c...d.e.f...g.h...
...a.b.c...g.h...d.e.f...
...a.d..e.g.b.c...h..f...
...gh...def...abc...
Not sure whether the fuz.el support it.

LeaderF has this feature, it's quite useful for fuzz searching, it's like this:
Below description is copied from https://github.com/Yggdroot/LeaderF/blob/master/README.md#usage for better understanding:
Thanks