OLD dropbox folder problem - please help

i'm having a dropbox issue that is a big problem.

i have someone i was collaborating. there was a FOLDER that i think THEY must have created - let's call it THEIR_FOLDER_NAME -when i gave them access (?) to a folder with their name on it and into which they have apparently been dumping data. i assume i crated a folder called MIKE's FOLDER or whatever and they created a subfolder in this folder since i would not have named it like this.

anyway - either THEY created this folder or I CREATED the parent folder a very long time ago.

so while they can show me a folder WITH THIS NAME and the content that they have been providing me i CANNOT FIND this folder in the dropbox folder on my desktop.

i DO SEE another folder that they seem to have also been providing me some data. and i DO SEE that they have occassionally been dropping date right into my DROPBOX parent folder so it gets dumped in with all my other content outside of the folder i now have for them.

for instance i now have a folder called "MIKE's #2 FOLDER" that i have been organizing all their info in.

but i cannot see the FOLDER which they have a lot of data in which is called "THEIR_FOLDER_NAME".

i can't find this folder in a spotlight search.

A. i can search each and every subfolder on my dropbox folder to see if it is hiding in their somewhow. or

B. i can try to see if i have an old dropbox folder somewhere that i cannot see right now?

i am sort of an idiot with this since i only see drobpox "from my end of things" and i don't really know how it all works.

this guy did send me a link to some files which came up in the drobpox UI online but since this has been so confusing i have just downloaded the files in the link and MANUALLY MOVED them to the folder i set up for them. just like i do with anything that gets dumped into my MAIN DROPBOX folder.

any ideas or explanations as to what i am doing wrong?

THANK YOU