The CONTAINSROW function expects a table expression for argument '', but a string or numeric express

Hi dkc 

You cannot use a condition to return a table or table expression. While SelectedCustTable doesn't return an error using this in another expression will cause an error.  Try this:

VAR SelectedCustTable01 =
    VALUES ( 'Hierarchy level Slicer'[HIERARCHY_LEVEL] )
VAR SelectedCustTable02 =
    ALL ( 'Hierarchy level Slicer'[HIERARCHY_LEVEL] )
VAR ThisCustomer =
    MAX ( 'FACTS_C4C Promos'[Hierarchy Level] )
RETURN
    IF (
        ISFILTERED ( 'Hierarchy level Slicer'[HIERARCHY_LEVEL] ),
        CALCULATE (
            COUNTROWS ( 'DIM_Customer Master' ),
            FILTER (
                'DIM_Customer Master',
                'DIM_Customer Master'[CUSTOMER_MASTER_DATA_HIERARCHY_LEVEL] = ThisCustomer
                    && CONTAINSROW (
                        SelectedCustTable01,
                        'DIM_Customer Master'[CUSTOMER_MASTER_DATA_HIERARCHY_LEVEL]
                    )
            )
        ),
        CALCULATE (
            COUNTROWS ( 'DIM_Customer Master' ),
            FILTER (
                'DIM_Customer Master',
                'DIM_Customer Master'[CUSTOMER_MASTER_DATA_HIERARCHY_LEVEL] = ThisCustomer
                    && CONTAINSROW (
                        SelectedCustTable02,
                        'DIM_Customer Master'[CUSTOMER_MASTER_DATA_HIERARCHY_LEVEL]
                    )
            )
        )
    )