The default location for all downloaded marketplace content can be found if you open the Epic Games launcher, go to settings and click the Edit Vault Cache Location.
If you mean the specific content that is downloaded to your specific project, then I don’t believe that. If I remember correctly, the content needs to be imported in the specific path for the engine to showcase it to you in the content browser.
However, once the content has been added and the game is launched, you can most likely move it to whatever location you wish.