Work with relational Exploration Views
Relational data in Exploration Views has limitations and differences
from dimensional data. One such instance is replacing measures on
columns. Measures derived from relational data are stacked blocks.
Replacement of the entire stacked block on the grid is not permitted. You
would need to do this on the summary bar. This behavior is consistent
with query items that are not measures. You may also notice that
expand, collapse and totals do not work with relational data sources.