To make it work as you intend you need parentheses (you need to enable experimental features Introducing beta (previously, experimental) features (including parentheses)!) because otherwise the operations will be computed left to right without knowledge of the grouping you have in mind.
You want to do (Field 1 is tree and field 2 is water and field 3 is field 4) **or** (Field 1 is tree and field 2 is liquid and field 3 is field 4)
or alternatively Field 2 is liquid or field 2 is water and field 3 is field 4 and Field 1 is tree