Need to watch for files in a particular directory and move them to a folder

I have a dropzone where users drop the file. Once the files are dropped they need to be moved to a directory based on who created/dropped the files. Main problem is the script has to wait till user drops 2 files of different formats

Example: file1.abc (These files can in multiple)
file2.xyz. file2.xyz will be a single file. Once these 2 files are dropped in the dropzone, script has to create a directory based on username and move those files into that directory.

Any help will be greatly appreciated.

I tried filtering based on owner but was not sure how to wait till both files are dropped

Need to watch for files in a particular directory and move them to a folder