Check out the some useful tips for using Google Drive
The already very powerful search in Google Drive now allows you to limit a search for files to a single file hierarchy.
This addition to Drive search is very simple and very powerful. By selecting a specific folder in Drive you can then search within it and its subfolders.
Within Google Drive:
Only folders that are within your My Drive or within Team Drives can be searched; if you have a folder that is shared with you, first add the folder to your My Drive.