Database tools and method for tree structured data?

I have a database structure which I believe is very common, and very general, so I’m wondering how this is tackled.

The database structured like:

 -> Project (Name of project) -> Category (simple word, ~20 categories) -> Study 

Study is a directory containing: – README with date & description (txt or md format) – Supporting files which can be any format (csv, xlsx, ptpx, keynote, text, markdown, pickled data frames, possible processing scripts, basically anything.)

Relationships among data: – Projects can have shared studies. – Studies can be related or new versions of older ones, but can also be completely independent.

Total size: – 1 TB, mostly due to supporting files found in studies.

What I want: – Search database for queries describing what we are looking for. – Eventually get pointed to proper study directory and/or contents, showing all the files. – Find which studies are similar based on description category, etc.

What is a good way to search such a database? Considering it’s so simple, do I even need a framework like sql?