From the expense reimbursements page, click the Tenant Groups link (1) in the Go To line.
Enter a group name in the Tenant Group field (2).
Select desired Available Tenants and use the arrows (3) to move them into the Associated Tenants column.
Click Update (4) to save your new tenant group.
To create an additional tenant group, click the Add New button (5).
To edit a tenant group, select it from the Expense Group menu (6), make your changes then click Update (4).