What is the configuration option to customize the groups inside the dock in CE.SDK and how can the asset sources be configured in the dock?

The groups inside dock can be configured via the dock option here.

Each group is separated by a gap towards the next group. To configure which asset sources are shown inside the dock, you will have to configure the "ui.elements.libraries.insert" property. There you can filter the insert entries and add or remove a sourceID for an entry/group.

For more information on customizing the asset library, please refer to our documentation.