How to set directory folder name into a function

Question

I am trying to upload files in the backend and I am successfully done it but the problem is I am uploading the files in a folder. So I need to parse the files so I need to define the folder name so that the file can be parsed. How can I define the folder name?

Here is the code, The folder name is uploads, but when I try to parse the file it says Error: ENOENT: no such file or directory, open '/uploads/undefined-1647961709285.xlsx'

const worksheetsArray = xlsx.parse('/uploads/' + filename);