You want to define the following CDS view entity with an input parameter:define view entity...

Comprehensive and Detailed Explanation from Exact Extract:

CDS view parameters must be defined with types that are visible in the ABAP Dictionary.

A. Built-in ABAP Dictionary type → ✅ Supported (e.g., CURR, CHAR).

D. Data element → ✅ Supported, as data elements are dictionary-level types.

B. Built-in ABAP type (like i, string) → ❌ Not supported directly, CDS requires dictionary-compatible types.

C. Component of a structure → ❌ Not supported directly; parameters cannot reference structure components.

This ensures that CDS definitions remain database-compatible and semantically rich, which is critical for RAP services.

Verified Study Guide Reference: ABAP CDS Development Guide – Defining View Parameters.