Hi @francoiswessels,
Do you want to copy the contents of a Dropbox folder (which contains sub-folders) to OneDrive for Business folder?
I assume that the sub-folders of your Dropbox Folder don't contain sub-folders, I have made a test on my side and please take a try with the following workaround:
- Add a proper trigger, here I use Flow Button trigger.
- Add a "List files in folder" action, specify Dropbox folder within Folder field.
- Add a "Apply to each", input parameter set to output of "List files in folder" action.
- Within "Apply to each", add a "Condition", left input box set to IsFolder dynamic content of "List files in folder" action, right input box set to true, within middle drop down, choose is equal to.
Within "If/yes" branch of Condition, add a "List files in folder 2" action, Folder field set to Path dynamic content of "List files in folder" action. Then add a "Apply to each 2" action, input parameter set to output of "List files in folder 2" action. Within "Apply to each 2" action, add a "Get file content 2" action, File field set to Id dynamic content of "List files in folder 2" action, add a "Create file 2" action, Folder Path field set to following formula:
/Test2/DisplayName dynamic content of "List files in folder 2" action
File Name field set to DisplayName dynamic content of "List files in folder 2" action, File Content field set to File Content of "Get file content 2" action.
Within "If/no" branch of Condition, add a "Get file content" action, File field set to Id dynamic content of "List files in folder" action. Then add a "Create file" action, specify Folder Path, File Name field set to DisplayName dynamic content of "List files in folder" action, File Content field set to File Content of "Get file content" action.
Image reference:

The flow works successfully as below:


Best regards,
Kris