Verify Item Category Assignment dynamically using validation rule

Summary:

We are on a transformation journey and are implementing Product Hub Portal. We are looking to achieve Item Validation with latest feature release on 22D version. Could you please help throw some light on whether following two validations are achievable?

Content (required):

Context of Problem Statement-

1) Purchasing Taxonomy is four level- Level1 (L1)-Level2(L2)-Level3(L3)-Level4(L4)

2) L4 is most granular (leaf level) and only level that can be assigned to items

3) Purchasing Category definition is-

3.A) Category_Name: L4 & Category_Description- L1.L2.L3.L4 (dot separated concatenation of all levels)

3.B) A DFF is defined at category definition level to identify if L4 is Material vs Services category