Left join two tables to one

Hi,

I have three tables: A,B,C.

A has a many-to-one relationship with B.

B has one-to-many relationship with C.

I need to left join B to A, and left join C to A.

Tables A and C do not have common columns.

I know how to join B to A. But I do not know how to join C to A.

ADDCOLUMNS (

A,

"JoinedB", related (B),

"JoinedC", ?)

Could you please help me?

In SQL the code would be sth like:

Select StockCode, Warehouse

From A as a

Left join B as b on a.StockCode=b.StockCode

Left join C as c on a."StockCode&Warehouse"=C."StockCode&Warehouse".

But in the PowerBi data model I am not allowed to create neither calculated table, nor calculated columns. I must use only existing relationships.