save yours in this folder!

If you want to have multiple folders, be aware they need to be in the top directory (Serum Presets/Presets/) as there are no sub-sub-directories accessible directly from in Serum.

So in other words, you could have:

Serum Presets/Presets/User (this folder)
Serum Presets/Presets/My Leads/
Serum Presets/Presets/My Bass/

but not:
Serum Presets/Presets/User/My Leads/

it is recommended to leave this “User” directory, as Serum attempts to open it when you click Save for a preset.