Sure that's possible, all date is stored in an sqlite database so the graphs are produced using sql. This is the query for the graph in the image:
query = '\"SELECT SUM(PC) AS GL4B_COUNT, GL4B, PC FROM fingerprint WHERE '+dateRangeSqlStr+' AND PC > 0 GROUP BY GL4B_ID ORDER BY GL4B_COUNT DESC LIMIT '+limit+';\"';
Edit: forgot to mention, this has nothing to do with facets or any other foobar2000 component. This is just old wsh_panel_mod using FB1.4. I do however use text_tools when I want to re-import the entire database (I'm constantly updating tags and data is only updated when played). Also using DB Browser for SQLite to access the database independently and test queries, and using firefox SQLite manager for the actual import.