It really depends. Do you have a dedicated team per level or is this all on your plate?

Personally, I try not to worry about the logic at the front-end of the stack. That's generally in the end users hands. The only time I worry about what's at the reporting level is if the other levels I do manage cannot support the levels above it. For example, if I have 100 different Excel sheets querying the data mart where the end users who are non-developers are creating Excel formulas to transform the data, there is absolutely no way I can manage that.

However, if you have actual visualization/report developers who are making these reports for end users, then ideally, it's up to them to maintain those respective logic. The only time it would matter to me, who is maintaining levels closer to the data, is when what they are doing can no longer be supported by the data mart for example. When that happens, then that's when you revisit the business requirements of the data mart and see what you can do to support their needs without having to worry about everything else above the data mart and beyond.

That's just what I follow simply because at some point, it is a lot to manage when it comes to the source data, the conforming of data to the data warehouse, the business process/logic when building out each data mart and eventually the cubes and front-end reports for whatever BI tools you are using to get the data in the end users hands. Thus, I focus more efforts on the source, data warehouse and data marts and try to offload the cubes and reports to someone else while trying to support those other teams the best I can with the data warehouse and data mart.

Unfortunately, that being said, you cannot bake every possible logic in the data mart or cube. But, you can do your best to try and support those missed questions as they get discovered later on down the road. Other than that, try not to limit the end users by not allowing them to conform the data on the front-end. Let them have that freedom until you cannot support their requirements and then step in.