I noticed difference between mapping in measures like this:
In first example there is full path from database but in second only the column from BMM.
Could you tell me what is the difference in action? How can I affect on that path?
You can derive your logical columns from physical columns or from other logical columns already mapped.
I can not see the image right, but it seems to me that the first image is a mapping logical column to physical and the second image you have a mapping of logical column from a logic column.
OBI will always seek its results database (with the exception of cache), but with the option to map a logical column from another, you gain time riding their calculations (not running)