Multiple level Database ideas

This should be easy but my brain hurts......

I am creating a database and im stuck on the layout design of it.

I want 3 levels


Level 1 = Site
Level 2 = Branch (can be 0-5 branches under each site, 0 will be just a site)
Level 3 = Department (can be 0-50+ departments under each branch, again 0 will be just a branch)


I have done this the obvious way (each column), when a filter is applied i lose everything.


Data table design.xlsm


Was trying to avoid filling in all the blanks - looks ugly when filtering and pivot tables do my head in.

I thought that might be the case, now to play with pivot i guess cheers

Thank you, this is easier - see told you there was an easy answer.