As described in note 1591837, the feature 'Key Figure Definition'(Explain Query) is a very helpful tool when you need to check query results. Use transaction RSRT (ABAP BICS or HTML mode) to execute the query, select a cell for which you require an explanation and then activate the extended context menu. The system now uses the definition and all of the properties belonging to this cell to create the simplest query possible. This query is then generated and executed. Additional Characteristics are automatically added as 'free characteristics' like 0REQUEST, 0INFOPROV, 1CUDIM and the 'Non-Visilble Drilldown Charateristics'. In the context menu, you can obtain additional information about the key figure and the origin of the individual selections by choosing 'Details'.
Review the example of note 1591837 (chapter [II.C]) and the videos about the transaction RSRT and the feature 'Key Figure definiotion' (Explain Query):
2164352 - Videos about transaction RSRT [VIDEO]
ABAP BICS Mode:
The 'Key Figure Definition' displays the result of the calculation (for a cell) in a hierarchically structured way which allows you to figure out where exactly in this chain of computations the problem occurs. This information can then be used to simplify the formula and just focus on a sub formula. It may also turn out that already a basic key figure (appears at the bottom of this hierarchy ) used in the formula has an incorrect(unexpected) value. In such a case you need to use all relevant filter restrictions (context menu function 'Details') in oder to compare the query result with the data in the provider. This can be done with the help of transaction LISTCUBE.
As of BW74 SP16, there is a new feature available which allows to jump from the 'Key Figure Definition' to the transaction LISTCUBE at which selections are transferred automatically(available in RSRT ABAP BICS Mode). See the following Example.