I know that you can query a cube by connecting from Excel to Analysis database and using formulas like cubevalue() or cubemember().
I also know that after converting the power pivot to formulas, you can access the attribute and the value related only by writing a text.
Example: for Branch Dimension, instead of writing
cubemember("connections";"[DimBranch].[Name].[All].[London])" )
you can write in the cell only "London". However, this won't work if you have a parent-child dimension and want to retrieve the amount for one of the intermediate levels.
Did anyone know about how can you avoid writing these formulas directly by the end-user ?
I´ve done this several times. I can describe the approach I´ve used in the past.
You need to define the input from the user, for example Fiscal Year, Fiscal Period,... and create a tab with a friendly layout for this solely purpose.
After that you create your pivot/pivots against the cube/s you want to query with the data extraction that you need (obiously these pivots will refer to the Fiscal Year and Period). Define the desired layout for these pivots (as you want them you be shown). Once You´ve done this, you need to convert into formulas these pivots, including parameters. You´ll see that values placed in the measure box contain a formula cubevalue which makes reference to the connection itself and several cubemembers. It makes reference to the measure as well.
The trickiest part comes now, when you need to modify your cubemember function to take value from the input, something like cubemember("connections";"[DimBranch].[Name].[All].["+MyReferenceCell+")" ), and you have your dimension picked up from a value entered by a user.
If you have as a matter of fact, serveral pivots referencing common dimensions, you need to make the reference this modified cubemember cell affected by user input, otherwise you have to modify all affected cubemembers in your pivots converted to formulas.
This has a really good advantage: depending on the excel´s version, all pivots are automatically recalulated if you change the value in the user´s input cell without hitting the refresh all button.
On the other hand, the disadvantage comes when your report in excel contains a list of values from a dimension which can grow. After converting pivots into formulas those new values for the dimension are lost. That´s why you can always place a control if you have the total value int he pivots regardless the dimension value.
I hope this helps.
Regards