When I run the following query no records are returned:
Right(([varlist_in]![path]),1)
I think you are leaving out some important details. That is not a query, that is a calculation. That, in and of itself, would not filter out records.
Are you doing a calculated field, and then putting something like "]" on the Criteria line of this field?
Did the data come off of the web or some other program? If so, there may be some special non-visible characters in there that TRIM does not affect (like the famous "non-breaking space")
If you identify a record that looks like ends in a right bracket, what does this calculated field return for that record?
Code:
Asc(Right([varlist_in]![path],1))