private void showLinkedFolderInViewedProject(DomainFile domainFile) {

		try {
			LinkedGhidraFolder linkedFolder =
				FolderLinkContentHandler.getReadOnlyLinkedFolder(domainFile);
			if (linkedFolder == null) {
				return;  // unsupported use
			}

			ProjectDataTreePanel dtp = projectDataPanel.openView(linkedFolder.getProjectURL());
			if (dtp == null) {
				return;
			}

			// Do not hang onto domainFile, linkedFolder or their underlying project data

			ProjectData viewedProjectData = dtp.getProjectData();
			DomainFolder domainFolder =
				viewedProjectData.getFolder(linkedFolder.getLinkedPathname());

			if (domainFolder != null) {
				// delayed to ensure tree is displayed
				Swing.runLater(() -> dtp.selectDomainFolder(domainFolder));
			}
		}
		catch (IOException e) {
			Msg.showError(this, projectDataPanel, "Linked-folder failure: " + domainFile.getName(),
				e);
		}

	}
builds the gui for the new front end
Ghidra/Framework/Project/src/main/java/ghidra/framework/main/FrontEndPlugin.java