Table associations

[Kgao]

I have 2 tables, one with costs and another with Revenue. Both table has Customer name as common identifier. When I filter by customer the Revenue amount changes while the Costs  does not (basically stays the same at total costs and not filtered customer costs)

How do i fix this or which step did I miss during the table associations

[marcus_sommer]

Just concatenate both tables because missing keys on one or both sides couldn't be associated.