src/vs/workbench/contrib/debug/browser/debugActionViewItems.ts/FocusSessionActionViewItem/getSessions
class FocusSessionActionViewItem:	protected getSessions(): ReadonlyArray<IDebugSession> {
		const showSubSessions = this.configurationService.getValue<IDebugConfiguration>('debug').showSubSessionsInToolBar;
		const sessions = this.debugService.getModel().getSessions();

		return showSubSessions ? sessions : sessions.filter(s => !s.parentSession);
	}