I've some "Customer Filters", the one you PGC gave as example and made some others. When displaying such an existing filter, I select it from the list and press "edit". This opens a new view, showing a list of statements.
To show such a statement, I select it and again press "edit".
Below a section named "add statement" the current statement is displayed, but some of the attributes are "crunched" (i.e. Types, Terrains, ..) behind the blue, underlined "expression text". This crunch ist done, when attribute has selected more than one data value, that means terrain with one selected value (e.g. 5) is shown as is.
I'd suggest that clicking such "blue, underlined" expression should show the content behind, but this does not work. Also flying over does not help to get its content again, neither viewing nor editing.