Trouble Creating Rules that Evaluate Sub-Folders

Even after reading the Help topic, and trying several rules, I'm still having trouble creating rules that evaluate files located in subfolders.
For example: This is a simplified and partial structure of my Documents Folder:
Documents (folder)
- Woodworking (folder)
- Workshop Related (folder)
- Carving (folder)
- Jigs and Plans (folder)
Filenames containing "Workshop" or 'workshop" are scattered throughout these 5 folders. If the filename contains "Workshop" or "workshop", I want to tag it with "Workshop" and I want to move it to the "Workshop Related" folder unless it's already in that folder.
Once I understand how to create rules that apply to all sub-folders, I'll create several rules using the same logic.
Thank you for any and all help.
For example: This is a simplified and partial structure of my Documents Folder:
Documents (folder)
- Woodworking (folder)
- Workshop Related (folder)
- Carving (folder)
- Jigs and Plans (folder)
Filenames containing "Workshop" or 'workshop" are scattered throughout these 5 folders. If the filename contains "Workshop" or "workshop", I want to tag it with "Workshop" and I want to move it to the "Workshop Related" folder unless it's already in that folder.
Once I understand how to create rules that apply to all sub-folders, I'll create several rules using the same logic.
Thank you for any and all help.