Test Plan Template

Hi,

When I am trying to create Child Test Plans under Master Test Plan 1 level below from High level Master Test Plan, I am unable to save the test plan as it errors out with the following msg

unable to make this test plan a master because it is already a child of another (*) test plan.

Is it possible to create multiple child test plans under Master Test Plan

Project ->Master Test Plan -> Child Test Plan -> Test Plan 1, Test Plan 2..
Below Child Test Plan, I want to create multiple children test plans.

Can this be done?

Thanks
Trinity