Functional Area assignment of SYS13 Account SKU Filter Module seems to be confusing.
Image in 1.6.5 Verify your model's Functional Area assignments and module organization is showing:
SYS13 Account SKU Filter Module
Functional Area: Hierarchies
Category: System Modules
However, in 1.5.7.1 it is mentioned to create Functional Area: Administration.
1.5.7.1 Create SYS13 Account SKU Filter Module