Creating organizations or managing the existing organizations can be done through the Manage Organization page available under Personnel Administration module.

Personnel Administration ->  Organization Management -> Manage Organization

Enter the Organization Name, Category like internal organization or external organization, Organization level (here HR Organization means the organization where employees exists) and other required details to create the organization record. Click the save button to save the data.

Once the organization is created it has to be attached to the organization tree as a node. This can be done through the Manage Organization Hierarchy page view option. 

Personnel Administration ->  Organization Management -> Manage Organization Hierarchy

Select organization from the left Organization Hierarchy section under which the new organization to be added and select & move the organization units from right section to left. Click the Save button to save the changes.