The Import button in the Sphere plug-in allows the loading of Sphere presets that were saved when using other DAWs and plug-in formats. Once the preset has been imported then you can re-save the preset in the DAWs built-in plug-in preset format.
For example, if you've saved a Sphere preset in UAD Console application you can then open the same preset in the AAX or VST version of the plug-in by clicking on Import and loading the preset file from the Universal Audio preset folder.
There are a few cases, such as Presonus Studio One, where this doesn't work because the DAW saves the preset in a binary format that Sphere doesn't know how to read. If that happens, Sphere will return an error that the preset is unrecognisable.