Composite mapping
I'm fairly new to OneStream. I've a requirement where if ICP is P213 and irrespective of any source entity then target entity will be "Chicago" and if Source entity is "E123" then target entity will be "New York". The problem which I'm facing is that I do have "E123" in source file where it only takes the mapping of "E123"->"New York". It doesn't even see if the ICP is P213.
I have a feeling that this is probably how you have setup the sequencing in your composite mapping rule rather than the dimension transformation sequence as suggested by MarcusH . The reason I say this is because you are using the source values as criteria and these are all available at the same time for each record processed irrespective of the dimension transformation sequence.
For example, you need to ensure that the composite mapping rule in your Entity dimension that evaluates a source condition where ICP value of P213, is sequenced to execute before any Entity mapping rule that evaluates a source condition where the value is E123