How can I return Observable of IEmployees with productName from allProducts$ in RXJS?

I want to retu Observable from GetEmployeeByID function that has a matching productName from allProducts$:

allProducts$ = this.state$.pipe(
map(x => x.allProducts as IProducts[] || [] as IProducts[]),
distinctUntilChanged());

GetEmployeeByID(Id: number): Observable<IEmployees> {
retu this.allEmployees$.pipe(
map(res => <IEmployees>res.find(data => data.id === Id) ?? { id: -1, name: "N/A", email: "N/A", gender: "N/A", productid: -1, productName: "N/A" } as IEmployees),...

How can I retu Observable of IEmployees with productName from allProducts$ in RXJS? WordPress ...