To retrieve the data for particular id in mapping table

a!localVariables(
    local!bID: 5,
    local!queryForC: a!queryEntity(
        cons!mapping_table,
        a!query(
            filter: a!queryFilter(
                "b",
                "=",
                local!bID
            ),
            pagingInfo: a!pagingInfo(
                1,
                100
            )
        )
    ),
    local!C_records: a!queryEntity(
        cons!Record_type_c,
        a!query(
            filter: a!queryFilter(
                "id",
                "in",
                local!queryForC.data.c
            ),
            pagingInfo: a!pagingInfo(
                1,
                100
            )
        )
    ),
    local!C_records
)

Thanks Danny