When attempting to copy an item, ShareGate Migrate displays the following warning:

This file/folder will not be copied because it is a symbolic link on a file/folder already copied at '<path>'

This error is caused when a file or folder is "Added To" another location. This creates a link to the item in another destination, meaning that when any of the "Added To" items are modified, all version of this item are modified. This is not supported in SharePoint. Therefore, only a single copy of the file will be kept at the destination.

There is no solution for creating the same behavior in SharePoint as this feature does not exist. You can remove the symbolic links (SymLinks) in Google Drive to identify the desired copy location or move the destination file once migrated to the preferred location.