Group by clause not used while running analysis on Oracle Analytics Cloud which leads to error "exceeding max number of rows"

Question

• I am on Oracle BI Administration Tool 12.2.8.0. and running analysis on OAC Classic Version.
• We have one product dimension and two cubes A and B.
• We have created product hierarchy on our product dimension from level 1 to 30 shown in pic1 and product details as leaf node shown in pic2.Pic1Pic2
• We have created similar keys as shown in pic3 from LEVEL1 to 30.Pic3 PRODUCT_WID is the primary key on Product Dimension Table.
• Logical Columns "Level(1-30) Product" are derived from existing columns using an expression as shown in pic4.Pic4
• If we use to create an analysis using Product Dimension and one aggregated column of the cube(A or B) shown in pic5 and when we check the logs of our analysis we could see it uses the “group by” clause in our physical query but if we use to create any analysis using Product Dimension and both cubes (A and B) then it is not able to use “group by” clause in our physical query, which cause in returning too many rows from it and leads to error "exceeding maximum number of rows".Pic5 Pic6 Pic7

Could you please let us know how do we resolve this issue, so that group by clause would be used in this scenario?