As a standard behaviour you can select only 1 organisation. But for the users would be great if the DHIS2 could provide an ability to select multiple organisations.
If you select the higher organization unit in the OU hierarchy, it will show the ones included in the pivot table creation. I think the way to do this is by creating a new table with only the OUs you want then select the higher OU.
I know if you select higher OU it will include all descendant OUs. But I need to select multiple OUs in the same level. As I understood there is no such ability, right?
Yes, so if you select the higher one, it will show the multiple descendants in the same level (the pivot table created in the Data Visualizer app should only have the OUs you want to appear).