A need of knowing in which BW reports is particular characteristics used is quite common in SAP BW area. Imagine that you need to analyze BW system for e.g. for auditing purposes.
Usually what you would do is to go to RSA1->Modeling->InfoObjects. Here you search for InfoObject and you go to its maintenance screen. In toolbar of this screen there is a Where-used button available. You hit this button and task is supposed to be completed in case you would get a list of BW reports where this InfoObject is used. Surprisingly this is not the case. You get the list of InfoProviders, Transformations, InfoObjects, Transfer Rules, 3.x InfoSource, etc. But not the reports!
What to the in this case? Luckily there is a special InfoObject transaction (RSD1) which does the same but for broader spectrum of objects. Peculiarity here is that once you are in RSD1 you cannot go via Where-Used button. This gives you the same what RSA1 gave – no reports list. What you need to do is go via menu->Edit->Where-Used List. Even more this functionality gives you a list of BE’x variables related to the InfoObject.
ABAP code which is behind this Functionality is function module RSDG_IOBJ_USAGE_SHOW.