The search-string supports a set of operator:
signifies AND operation.
| signifies OR operation.
negates a single token.
at the end of a term signifies a prefix query.( and ) signify precedence.
~N after a word signifies edit distance (fuzziness) with a number representing Levenshtein distance.
~N after a phrase signifies slop amount.
There is no possibility to set the field, this is preset in the search-expression. The search-expression itself is a fulltext OR ngram on _allFields with boosting of displayName(5) and name(3)