private static IContributionItem makeCreateContributionItem(
        @Nullable IWorkbenchPartSite site, String objectType, String objectTypeName, DBPImage objectIcon, boolean isFolder)
    {
        if (site == null) {
            return DUMMY_CONTRIBUTION_ITEM;
        }
        CommandContributionItemParameter params = new CommandContributionItemParameter(
            site,
            NavigatorCommands.CMD_OBJECT_CREATE,
            NavigatorCommands.CMD_OBJECT_CREATE,
            CommandContributionItem.STYLE_PUSH
        );
        Map<String, String> parameters = new HashMap<>();
        parameters.put(NavigatorCommands.PARAM_OBJECT_TYPE, objectType);
        parameters.put(NavigatorCommands.PARAM_OBJECT_TYPE_NAME, objectTypeName);
        if (objectIcon != null) {
            parameters.put(NavigatorCommands.PARAM_OBJECT_TYPE_ICON, objectIcon.getLocation());
        }
        if (isFolder) {
            parameters.put(NavigatorCommands.PARAM_OBJECT_TYPE_FOLDER, String.valueOf(true));
        }
        params.parameters = parameters;

        return new CommandContributionItem(params);
    }
Sorry, this is a bit over-complicated handler. Historical reasons.
It can create object of specified type (in parameters) or for current selection.
Dynamic menu "Create" fills elements with parameters. Direct contribution of create command will create nearest
object type according to navigator selection.
plugins/org.jkiss.dbeaver.ui.navigator/src/org/jkiss/dbeaver/ui/navigator/actions/NavigatorHandlerObjectCreateNew.java