Many to Many Dimensions Rollup

Given: End user can input in the following 9 columns as a dropdown(List Format) in the Input Free Form. Free Form is a module having a Numbered List applied which is having these Line Items as a List Format so that users can choose from the dropdown.

Following is the count of List Members in the lowest level.

Requirement: We need to create a report which combines Data based on the 5 Dimensions (Department, Account, Analysis, Industry, Geography). 

The problem I'm Facing: Size Constraints.

Workspace size is only 130GB.

If we directly create a module having all the 5 Dimensions. Then It will exceed our 130GB Limit.

I have tried on a solution to create an intermediate list and create all the Combinations of 5 Dimensions and then aggregate my Data and Show it in the Report. But Challenge there is then I Created a Final Module (name Cost Opex Module) Having Users, Time, Analysis and Account as a Dimension. Then I will be making user-specific Dropdowns for Department, Industry, and Geography.

There as for Department, Industry, and Geography I have to create a Fake List as I want users to select all the Levels. Then I created a User Filter for our Intermediate Module. So If I add User List with Intermediate List and create a filter I'm able to achieve the functionality but then I have Size Constraints.

Looking for better solution for this problem statement.