Using Anaplan to filter on Anaplan

I'm really new to Anaplan so apologies if this is a simple one.

My hierarchy is set up as follows

Department
Hiring Role
Hiring Role_Site
Forecasting Task

I want to be able to filter on site & department separately. However, I can't add site into the hierarchy as the same site can exist for multiple departments.

I've added it as line item as I can tell from the name of the forecasting task which site it should be worked from but, with it being a line item, I can't figure out how to add it as a context selector.