You would have been fine if you had just mass deleted the folder contents before deleting the folder itself, but now your only option to clean up the mess using Bitwarden (besides a manual hunt-and-peck) would be doing this by means of a script using the CLI. @Neuron5569’s suggestion of making use of your Google export file is also good, and may not even require use of the CLI — instead, export your Bitwarden vault in .CSV format, which will allow you to remove the recently imported data as follows:
Open the Bitwarden .CSV export file in Excel, and insert 630 empty rows between the column headers and the first Bitwarden vault item.
Find one or more data columns in your Google export that will uniquely match only items that you had previously imported (and not match any items that were in your vault prior to the recent Google import) — if you don’t think it’s possible to avoid duplicates that are indistinguishable from pre-existing vault items (from before the Google import), then some additional data conditioning procedures will be needed before proceeding. Assuming that you find a set of suitable columns, copy the corresponding data (omitting the column headers) from the Google export file into the empty rows that you had created (starting at Row #2) in the Bitwarden .CSV file — place the copied data in the appropriate column(s), where the duplicate data can be found, and make a note of the column headers. Important: Do not paste any data into the type
column!
Next, select all non-empty columns and rows in the Bitwarden .CSV, and open the data de-duplication tool (in my version of Excel, this can be found under Data > Data Tools > Remove Duplicates). Enable the option “My data has headers” before proceeding. Deselect all columns, then select only those columns where you had pasted data in Step above. Click OK; you should seen a success notification that says something to the effect “630 duplicate values were found and removed”.
In the deduplicated Bitwarden .CSV file, delete Rows 2–631 (i.e., the data that you had pasted from the Google export); completely remove the rows — don’t just clear their contents. When you are done, there should be no rows left that have an empty value in the type
column.
Save the modified .CSV file, purge the contents of your vault, and import the modified .CSV file by specifying the file format as “Bitwarden (csv)”.
If you’re going to attempt the above, I would strongly advise that you also create a password-protected .JSON export before starting, and (if you have a Premium subscription) ensuring that you have backup copies of any files that you may have attached to your vault items.