Looks like Charles has a handle on this but my question is the filter part. Do you want any row in sheet 1 to be hidden if it contains any of the values in columns C or D on Sheet 3? That is the only way I can see this doing what you want. If that is what you are looking for let us know. Charles I have the idea on how to do this but since you are first on scene I will only provide it if you need.

Thanks